---
title: "Firewood Calculator: Measure Your Cord, Catch Shortfalls, and Know Your Heat Before You Buy"
canonical: "https://theyieldgrid.com/firewood-calculator/"
model_id: "tyg-2389"
model_version: "1.0.0"
last_reviewed: "2026-08-20T09:59:29"
reviewed_by: "Umer Hayiat"
---

# Firewood Calculator: Measure Your Cord, Catch Shortfalls, and Know Your Heat Before You Buy

> Canonical calculator: [https://theyieldgrid.com/firewood-calculator/](https://theyieldgrid.com/firewood-calculator/)

## What this calculator does

Home - Free Gardening Calculators & Tools - Firewood Calculator: Measure Your Cord, Catch Shortfalls, and Know Your Heat Before You Buy Buying or measuring firewood is deceptively straightforward until the stack arrives and something feels off. A delivery described as a “cord” might occupy far less space than the legal standard, or a stack you’ve been building all season might fall short of what’s actually needed. The problem is almost always the same: volume gets estimated by eye rather than calculated from dimensions. Stack length, depth (log length), and height each multiply together, and even a modest error in one dimension compounds into a significant shortfall of actual cubic feet.

## Inputs

| Input | ID | Type | Unit | Range or choices | Required |
|---|---|---|---|---|---|
| Stack Length | `fwcord_length` | number | feet | 0.1 to 9999 | No |
| Stack Width | `fwcord_width` | number | std = 4 ft | 0.1 to 9999 | No |
| Stack Height | `fwcord_height` | number | feet | 0.1 to 9999 | No |
| Wood Type (for BTU estimate) | `fwcord_wood` | select | for BTU estimate | Oak (23.6M BTU/cord) — Hardwood, excellent = `23600000`; Hickory (21.6M BTU/cord) — Hardwood, excellent = `21600000`; Hard Maple (20.0M BTU/cord) — Hardwood, very good = `20000000`; White Ash (18.7M BTU/cord) — Hardwood, very good = `18700000`; Birch (17.5M BTU/cord) — Hardwood, good = `17500000`; Cherry (15.0M BTU/cord) — Hardwood, good = `15000000`; Soft Maple (14.0M BTU/cord) — Mixed wood = `14000000`; Pine (11.0M BTU/cord) — Softwood, low = `11000000`; Poplar / Aspen (8.9M BTU/cord) — Softwood, very low = `8900000` | No |

## Outputs

| Output ID | Default state |
|---|---|
| `fwcord_length_err` |  |
| `fwcord_width_err` |  |
| `fwcord_height_err` |  |
| `fwcord_results` | Full Cords — cords — Cubic Feet — Face Cords Full Cord Gauge (128 cu ft = 1 cord) Rip-Off Detector: Is This a Full Cord? Approximate Heat Value (BTU) — million BTU Cord Conversion Reference Cord Type Cu Ft Dimensions (typical) Notes |
| `fwcord_out_primary` | — |
| `fwcord_out_cubicft` | — |
| `fwcord_out_facecords` | — |
| `fwcord_out_btu` | — |

## Formula and method

The core math converts your measured stack dimensions directly into the legal cord equivalent, making shortfalls immediately visible. Show the calculation steps Step-by-Step Formula Step 1: Gross cubic feet Cubic Feet = Stack Length (ft) x Stack Width (ft) x Stack Height (ft) Example: 8 ft x 4 ft x 4 ft = 128.0 cu ft Step 2: Full cords Full Cords = Cubic Feet / 128 The value 128 is the legally defined volume of one full cord in the United States (4 ft x 4 ft x 8 ft). Division is straightforward; results are rounded to two decimal places. Example: 128.0 / 128 = 1.00 cord Step 3: Face cords Face Cords = Cubic Feet / 42.6 A face cord (also called a rick) is one row of wood 4 feet high and 8 feet long, stacked one log deep at a 16-inch (approximately 1.33 ft) cut length: 4 x 8 x 1.33 = 42.56, rounded to 42.6 cu ft. Results are rounded to two decimal places. Example: 128.0 / 42.6 = 3.00 face cords Step 4: BTU estimate Total BTU = Full Cords x BTU per cord for selected species Each species has a published average BTU value per full cord, based on air-dried hardwood or softwood data. The result is displayed in millions of BTU for readability. Example (Oak): 1.00 x 23,600,000 = 23,600,000 BTU = 23.6 million BTU Assumptions and Limits Gross stack volume is always larger than actual wood volume. Air gaps between logs typically account for 15 to 20 percent of a stacked pile. This tool measures gross volume; the usable wood volume is somewhat less. BTU values assume properly seasoned wood at approximately 20 percent moisture content. Green (freshly cut) wood can contain 45 to 50 percent moisture, reducing effective heat output substantially. Log shape variation affects packing. Round logs with bark leave larger gaps than split, angular pieces. A pile of unsplit rounds may have significantly more air space than a tightly stacked pile of split wood at the same dimensions. Face cord volume (42.6 cu ft) assumes exactly 16-inch cut lengths. Logs cut to 18 inches, 20 inches, or 24 inches produce a proportionally larger face cord volume and a different full-cord equivalent ratio. The 128-cubic-foot cord standard is federal and applies in most U.S. states, but some states define the cord differently or regulate terms like “face cord” and “rick” separately. Local weights-and-measures regulations take precedence. This calculator does not account for settling. A freshly stacked pile that dries and settles over weeks may lose measurable height. A stack measured immediately after delivery may read slightly larger than its settled volume. All inputs are assumed to represent a single, roughly rectangular stack. Irregularly shaped piles or multiple separate stacks should be measured and calculated individually, then summed. Step 1: Gross cubic feet Cubic Feet = Stack Length (ft) x Stack Width (ft) x Stack Height (ft) Example: 8 ft x 4 ft x 4 ft = 128.0 cu ft Step 2: Full cords Full Cords = Cubic Feet / 128 The value 128 is the legally defined volume of one full cord in the United States (4 ft x 4 ft x 8 ft). Division is straightforward; results are rounded to two decimal places. Example: 128.0 / 128 = 1.00 cord Step 3: Face cords Face Cords = Cubic Feet / 42.6 A face cord (also called a rick) is one row of wood 4 feet high and 8 feet long, stacked one log deep at a 16-inch (approximately 1.33 ft) cut length: 4 x 8 x 1.33 = 42.56, rounded to 42.6 cu ft. Results are rounded to two decimal places. Example: 128.0 / 42.6 = 3.00 face cords Step 4: BTU estimate Total BTU = Full Cords x BTU per cord for selected species Each species has a published average BTU value per full cord, based on air-dried hardwood or softwood data. The result is displayed in millions of BTU for readability. Example (Oak): 1.00 x 23,600,000 = 23,600,000 BTU = 23.6 million BTU

## Verified worked examples

### Example 1: A Textbook Full Cord

Stack Length: 8 ft Stack Width (log length): 4 ft Stack Height: 4 ft Wood Type: Oak (23.6 million BTU per cord) Result: 128.0 cubic feet | 1.00 full cord | 3.00 face cords | 23.6 million BTU This is the textbook definition of a legal cord: 4 ft x 4 ft x 8 ft = 128 cubic feet. Oak at 23.6 million BTU per cord is one of the highest heat-density hardwoods available. A single cord of seasoned oak can run a mid-efficiency wood stove for roughly 260 hours at continuous output, depending on the unit’s rated BTU/hr.

### Example 2: A Common Short Delivery

Stack Length: 8 ft Stack Width (log length): 4 ft Stack Height: 3 ft Wood Type: Birch (17.5 million BTU per cord) Result: 96.0 cubic feet | 0.75 full cords | 2.25 face cords | 13.1 million BTU A stack that is only 3 feet tall instead of 4 feet loses a full quarter of a cord. This scenario is common with deliveries where the driver stacks loosely or loads to a visual impression of height rather than measuring. If you paid for a full cord at a going rate, you received only three-quarters of what you purchased. The Rip-Off Detector in the tool flags this as a below-full-cord result.

### Example 3: One Face Cord (Rick)

Stack Length: 8 ft Stack Width (log length): 1.33 ft (16-inch logs) Stack Height: 4 ft Wood Type: Pine (11.0 million BTU per cord) Result: 42.6 cubic feet | 0.33 full cords | 1.00 face cord | 3.63 million BTU A single face cord of 16-inch pine is roughly one-third of a full cord and provides the lowest heat density among common firewood species. This is a realistic starting supply for shoulder-season heating or occasional fires, but it falls far short of what most homes need for a primary heat source through a full winter.

## Assumptions

The core math converts your measured stack dimensions directly into the legal cord equivalent, making shortfalls immediately visible. Show the calculation steps Step-by-Step Formula Step 1: Gross cubic feet Cubic Feet = Stack Length (ft) x Stack Width (ft) x Stack Height (ft) Example: 8 ft x 4 ft x 4 ft = 128.0 cu ft Step 2: Full cords Full Cords = Cubic Feet / 128 The value 128 is the legally defined volume of one full cord in the United States (4 ft x 4 ft x 8 ft). Division is straightforward; results are rounded to two decimal places. Example: 128.0 / 128 = 1.00 cord Step 3: Face cords Face Cords = Cubic Feet / 42.6 A face cord (also called a rick) is one row of wood 4 feet high and 8 feet long, stacked one log deep at a 16-inch (approximately 1.33 ft) cut length: 4 x 8 x 1.33 = 42.56, rounded to 42.6 cu ft. Results are rounded to two decimal places. Example: 128.0 / 42.6 = 3.00 face cords Step 4: BTU estimate Total BTU = Full Cords x BTU per cord for selected species Each species has a published average BTU value per full cord, based on air-dried hardwood or softwood data. The result is displayed in millions of BTU for readability. Example (Oak): 1.00 x 23,600,000 = 23,600,000 BTU = 23.6 million BTU Assumptions and Limits Gross stack volume is always larger than actual wood volume. Air gaps between logs typically account for 15 to 20 percent of a stacked pile. This tool measures gross volume; the usable wood volume is somewhat less. BTU values assume properly seasoned wood at approximately 20 percent moisture content. Green (freshly cut) wood can contain 45 to 50 percent moisture, reducing effective heat output substantially. Log shape variation affects packing. Round logs with bark leave larger gaps than split, angular pieces. A pile of unsplit rounds may have significantly more air space than a tightly stacked pile of split wood at the same dimensions. Face cord volume (42.6 cu ft) assumes exactly 16-inch cut lengths. Logs cut to 18 inches, 20 inches, or 24 inches produce a proportionally larger face cord volume and a different full-cord equivalent ratio. The 128-cubic-foot cord standard is federal and applies in most U.S. states, but some states define the cord differently or regulate terms like “face cord” and “rick” separately. Local weights-and-measures regulations take precedence. This calculator does not account for settling. A freshly stacked pile that dries and settles over weeks may lose measurable height. A stack measured immediately after delivery may read slightly larger than its settled volume. All inputs are assumed to represent a single, roughly rectangular stack. Irregularly shaped piles or multiple separate stacks should be measured and calculated individually, then summed. Gross stack volume is always larger than actual wood volume. Air gaps between logs typically account for 15 to 20 percent of a stacked pile. This tool measures gross volume; the usable wood volume is somewhat less. BTU values assume properly seasoned wood at approximately 20 percent moisture content. Green (freshly cut) wood can contain 45 to 50 percent moisture, reducing effective heat output substantially. Log shape variation affects packing. Round logs with bark leave larger gaps than split, angular pieces. A pile of unsplit rounds may have significantly more air space than a tightly stacked pile of split wood at the same dimensions. Face cord volume (42.6 cu ft) assumes exactly 16-inch cut lengths. Logs cut to 18 inches, 20 inches, or 24 inches produce a proportionally larger face cord volume and a different full-cord equivalent ratio. The 128-cubic-foot cord standard is federal and applies in most U.S. states, but some states define the cord differently or regulate terms like “face cord” and “rick” separately. Local weights-and-measures regulations take precedence. This calculator does not account for settling. A freshly stacked pile that dries and settles over weeks may lose measurable height. A stack measured immediately after delivery may read slightly larger than its settled volume. All inputs are assumed to represent a single, roughly rectangular stack. Irregularly shaped piles or multiple separate stacks should be measured and calculated individually, then summed. Critical Warnings A “cord” is a legal unit. In the U.S., the National Institute of Standards and Technology (NIST) Handbook 130 defines a cord as 128 cubic feet of stacked wood. Selling wood described as a “cord” when the actual measured volume is less is a violation of weights-and-measures law in most states. Measure before you stack, not after. Face cord confusion is the leading cause of firewood overpayment. A face cord is approximately one-third of a full cord. If a supplier quotes a price “per cord” but delivers a face cord, you receive about one-third the wood you paid for. The terms “rick,” “rank,” “face cord,” and “fireplace cord” are not standardized and should always be converted to cubic feet before comparing prices. BTU estimates degrade sharply with wet wood. The heat values in this tool assume seasoned firewood. Burning green wood does not just produce less heat; it also increases creosote buildup in flue systems, creating a fire hazard. A firewood thermometer or moisture meter is the only reliable way to confirm seasoning. Stack height measurement errors compound fast. Because height is one of three multiplied dimensions, a one-foot undercount in a standard 8 x 4 stack removes 32 cubic feet, which is a quarter of a cord. Always measure, never estimate by eye. Minimum Standards A full cord must equal at least 128 cubic feet of stacked wood, verified by measuring length, width, and height in feet and multiplying. Firewood sold by the “cord” must be accompanied by a receipt showing the quantity and unit of measure in most U.S. states. Request this documentation from any supplier before payment. Seasoned firewood suitable for burning should test at or below 20 percent moisture content. Above that threshold, heat output drops and combustion byproducts increase. Competitor Trap: Most firewood volume guides online simply show you the formula (L x W x H / 128) and move on. What they skip is the step that actually protects you: the comparison against the legal standard before you finish stacking. By the time a pile is fully stacked, you have lost leverage with your supplier. Calculate your cord count from the delivery measurements or from the truck bed dimensions before the wood leaves the vehicle. If you heat a barn or outbuilding in addition to your home, the barn ventilation calculator can help you size the airflow needs that directly affect how much wood you burn per heating season. Winter resource planning, whether it involves firewood, hay, or feed, benefits from working the numbers before the season starts rather than during it; the winter cattle feed calculator uses the same “calculate now, adjust early” logic for livestock operations. A full cord must equal at least 128 cubic feet of stacked wood, verified by measuring length, width, and height in feet and multiplying. Firewood sold by the “cord” must be accompanied by a receipt showing the quantity and unit of measure in most U.S. states. Request this documentation from any supplier before payment. Seasoned firewood suitable for burning should test at or below 20 percent moisture content. Above that threshold, heat output drops and combustion byproducts increase. Competitor Trap: Most firewood volume guides online simply show you the formula (L x W x H / 128) and move on. What they skip is the step that actually protects you: the comparison against the legal standard before you finish stacking. By the time a pile is fully stacked, you have lost leverage with your supplier. Calculate your cord count from the delivery measurements or from the truck bed dimensions before the wood leaves the vehicle. If you heat a barn or outbuilding in addition to your home, the barn ventilation calculator can help you size the airflow needs that directly affect how much wood you burn per heating season. Winter resource planning, whether it involves firewood, hay, or feed, benefits from working the numbers before the season starts rather than during it; the winter cattle feed calculator uses the same “calculate now, adjust early” logic for livestock operations.

## Limitations and safety

Gross stack volume is always larger than actual wood volume. Air gaps between logs typically account for 15 to 20 percent of a stacked pile. This tool measures gross volume; the usable wood volume is somewhat less. BTU values assume properly seasoned wood at approximately 20 percent moisture content. Green (freshly cut) wood can contain 45 to 50 percent moisture, reducing effective heat output substantially. Log shape variation affects packing. Round logs with bark leave larger gaps than split, angular pieces. A pile of unsplit rounds may have significantly more air space than a tightly stacked pile of split wood at the same dimensions. Face cord volume (42.6 cu ft) assumes exactly 16-inch cut lengths. Logs cut to 18 inches, 20 inches, or 24 inches produce a proportionally larger face cord volume and a different full-cord equivalent ratio. The 128-cubic-foot cord standard is federal and applies in most U.S. states, but some states define the cord differently or regulate terms like “face cord” and “rick” separately. Local weights-and-measures regulations take precedence. This calculator does not account for settling. A freshly stacked pile that dries and settles over weeks may lose measurable height. A stack measured immediately after delivery may read slightly larger than its settled volume. All inputs are assumed to represent a single, roughly rectangular stack. Irregularly shaped piles or multiple separate stacks should be measured and calculated individually, then summed. Critical Warnings A “cord” is a legal unit. In the U.S., the National Institute of Standards and Technology (NIST) Handbook 130 defines a cord as 128 cubic feet of stacked wood. Selling wood described as a “cord” when the actual measured volume is less is a violation of weights-and-measures law in most states. Measure before you stack, not after. Face cord confusion is the leading cause of firewood overpayment. A face cord is approximately one-third of a full cord. If a supplier quotes a price “per cord” but delivers a face cord, you receive about one-third the wood you paid for. The terms “rick,” “rank,” “face cord,” and “fireplace cord” are not standardized and should always be converted to cubic feet before comparing prices. BTU estimates degrade sharply with wet wood. The heat values in this tool assume seasoned firewood. Burning green wood does not just produce less heat; it also increases creosote buildup in flue systems, creating a fire hazard. A firewood thermometer or moisture meter is the only reliable way to confirm seasoning. Stack height measurement errors compound fast. Because height is one of three multiplied dimensions, a one-foot undercount in a standard 8 x 4 stack removes 32 cubic feet, which is a quarter of a cord. Always measure, never estimate by eye. Minimum Standards A full cord must equal at least 128 cubic feet of stacked wood, verified by measuring length, width, and height in feet and multiplying. Firewood sold by the “cord” must be accompanied by a receipt showing the quantity and unit of measure in most U.S. states. Request this documentation from any supplier before payment. Seasoned firewood suitable for burning should test at or below 20 percent moisture content. Above that threshold, heat output drops and combustion byproducts increase. Competitor Trap: Most firewood volume guides online simply show you the formula (L x W x H / 128) and move on. What they skip is the step that actually protects you: the comparison against the legal standard before you finish stacking. By the time a pile is fully stacked, you have lost leverage with your supplier. Calculate your cord count from the delivery measurements or from the truck bed dimensions before the wood leaves the vehicle. If you heat a barn or outbuilding in addition to your home, the barn ventilation calculator can help you size the airflow needs that directly affect how much wood you burn per heating season. Winter resource planning, whether it involves firewood, hay, or feed, benefits from working the numbers before the season starts rather than during it; the winter cattle feed calculator uses the same “calculate now, adjust early” logic for livestock operations.

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## Provenance

- Model ID: `tyg-2389`
- Model version: `1.0.0`
- Reviewed by: Umer Hayiat
- Page modified: 2026-08-20T09:59:29
- Runtime SHA-256: `61bf7c48d90edf774d8fe38ea03143322d0d331340ffd3b25e7f5aa8775732db`

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