wood-calc 🌲

A precise, zero-dependency TypeScript calculator for woodworking material planning, moisture science, and joinery strength. Stop guessing and start building with confidence.

✨ Features

✅ Board Feet & Linear Feet – Calculate lumber volume and length from dimensions, supporting nominal sizes (2×4, etc.) and quantities.

✅ Sheet Material Planning – Determine plywood or MDF sheet counts with configurable waste factors.

✅ Moisture Content & Equilibrium – Compute MC from weight, predict EMC for your shop environment, and estimate drying times.

✅ Wood Shrinkage Prediction – Forecast dimensional changes for 10 common species when moisture content changes.

✅ Joinery Strength Calculator – Estimate the strength of 8 joint types (mortise-tenon, dovetail, box joint, lap, butt, dowel, biscuit, pocket hole) based on wood species, dimensions, and glue area.

📦 Installation

bash
bun add wood-calc

or

npm install wood-calc

🚀 Usage

Board Feet

import { calculateBoardFeet } from "wood-calc";

const result = calculateBoardFeet({
thickness: 1.5,
width: 3.5,
length: 96,
quantity: 4,
});
console.log(result.value); // ≈ 14.0 board feet

Sheet Count

import { calculateSheetCount } from "wood-calc";

const sheets = calculateSheetCount({
area: 5760,
sheetWidth: 48,
sheetLength: 96,
wasteFactor: 0.1,
});
console.log(sheets.value); // 2 sheets

Moisture Content

import { calculateMoistureContent, calculateEquilibriumMC } from "wood-calc";

const mc = calculateMoistureContent({ wetWeight: 12.5, dryWeight: 10.0 });
console.log(mc); // 25.0%

const emc = calculateEquilibriumMC({ temperature: 70, relativeHumidity: 50 });
console.log(emc); // ≈ 9.1%

Wood Shrinkage

import { calculateShrinkage, WoodSpecies } from "wood-calc";

const shrinkage = calculateShrinkage(WoodSpecies.Oak, 15, 8);
console.log(shrinkage.radial); // radial shrinkage %
console.log(shrinkage.tangential); // tangential shrinkage %
console.log(shrinkage.volumetric); // volumetric shrinkage %

Joinery Strength

import { calculateJoineryStrength, JoineryType, WoodSpecies } from "wood-calc";

const result = calculateJoineryStrength({
joineryType: JoineryType.MortiseTenon,
species: WoodSpecies.Oak,
jointWidth: 2,
jointDepth: 3,
glueArea: 12,
reinforced: false,
});
console.log(result.estimatedStrength); // ≈ 29544 lbs
console.log(result.maxRecommendedLoad); // ≈ 9848 lbs (with 3× safety factor)
console.log(result.failureMode); // "Tenon shear or mortise wall splitting"

Compare Joint Types

import { compareJoints, WoodSpecies } from "wood-calc";

const ranked = compareJoints(WoodSpecies.Oak, 2, 3, 10);
ranked.forEach(({ joineryType, result }) => {
console.log(${joineryType}: ${result.estimatedStrength} lbs);
});
// Sorted strongest to weakest

Get Species Data

import { getSpeciesData, WoodSpecies } from "wood-calc";

const oak = getSpeciesData(WoodSpecies.Oak);
console.log(oak.shearStrength); // 1780 psi
console.log(oak.specificGravity); // 0.6
console.log(oak.modulusOfRupture); // 14300 psi

📐 API Reference

Lumber

• calculateBoardFeet(input) — Board feet from dimensions
• calculateLinearFeet(input) — Linear feet from length × quantity
• calculateSheetCount(input) — Sheet count with waste factor
• calculateTotalBoardFeet(boards) — Sum board feet across multiple boards
• calculateBoardFeetNominal(t, w, l, qty) — Board feet using nominal sizes (2×4, etc.)

Moisture

• calculateMoistureContent(input) — MC% from wet/dry weights
• calculateEquilibriumMC(input) — EMC from temperature & humidity
• calculateShrinkage(species, initialMC, finalMC) — Dimensional shrinkage
• getShrinkageCoefficients(species) — Species shrinkage data
• getFSPFactor(mc) — Fiber saturation point factor
• estimateDryingTime(thickness, initialMC, targetMC, temp, rh) — Drying time estimate

Joinery

• calculateJoineryStrength(input) — Estimate joint strength in lbs-force
• getSpeciesData(species) — Full mechanical properties for a species
• compareJoints(species, width, depth, glueArea) — Rank all 8 joint types by strength

Enums

• WoodSpecies — Oak, Pine, Maple, Walnut, Cherry, DouglasFir, Cedar, Poplar, Hardwood, Softwood
• JoineryType — MortiseTenon, Dovetail, BoxJoint, LapJoint, ButtJoint, Dowel, Biscuit, PocketHole

🧪 Testing

bash
bun test

📄 License

MIT