Material Waste Calculator
How much extra material to buy for a waste percentage, and what that waste actually costs you.
At a glance
- What you enter
- Material the project needs, Expected waste, Price per unit, Share of the waste you will keep and reuse
- What you get
- Extra material the waste adds, Material to buy, Material to buy, rounded up, Total purchase cost, Cost of waste you will not reuse, Effective cost per unit delivered, Uplift on the material bill, Waste as a share of what you buy
- Formula shown
- Yes, every step, right below your results.
- Cost and privacy
- Free, no account needed, and nothing you type is stored.
See worked examples ↓ Read the FAQ ↓ Share this calculator ↓
Results are estimates for general information only, always verify with a professional or official source before acting on them.
How to use the Material Waste Calculator
- 1 Enter Material the project needs (units), In whatever unit you are buying: board feet, sheets, linear feet or square feet.
- 2 Enter Expected waste (%), Ten to fifteen percent for clear stock, twenty to thirty for a low grade or heavy grain matching.
- 3 Enter Price per unit (USD)
- 4 Enter Share of the waste you will keep and reuse (%), Offcuts held for the next project are not wasted money, so the tool deducts them at the edge.
- 5 Press Calculate. You get Extra material the waste adds, Material to buy, Material to buy, rounded up, Total purchase cost, Cost of waste you will not reuse, Effective cost per unit delivered, Uplift on the material bill, Waste as a share of what you buy, and every intermediate step stays visible under "How is this calculated?"
- 6 Change one number at a time to see what moves the result, that is usually the most useful thing a calculator can tell you.
Worked examples
Real numbers run through this calculator. Open any example to load it into the form above and change it.
Twenty board feet of walnut at ten dollars
A project needing 20 board feet, with fifteen percent waste and no reuse.
You enter
- Material the project needs
- 20 units
- Expected waste
- 15%
- Price per unit
- $10.00
- Share of the waste you will keep and reuse
- 0%
You get
- Extra material the waste adds
- 3.00 units
- Material to buy
- 23.00 units
- Material to buy, rounded up
- 23
- Total purchase cost
- $230.00
- Cost of waste you will not reuse
- $30.00
- Effective cost per unit delivered
- $11.50
- Uplift on the material bill
- 15.0%
- Waste as a share of what you buy
- 13.0%
Buy 23 board feet. The waste costs 30 dollars on top of a 200 dollar bill.
Twelve sheets of plywood
A cabinet job needing 12 sheets at 55 dollars, with twenty percent waste.
You enter
- Material the project needs
- 12 units
- Expected waste
- 20%
- Price per unit
- $55.00
- Share of the waste you will keep and reuse
- 25%
You get
- Extra material the waste adds
- 2.40 units
- Material to buy
- 14.40 units
- Material to buy, rounded up
- 15
- Total purchase cost
- $792.00
- Cost of waste you will not reuse
- $99.00
- Effective cost per unit delivered
- $66.00
- Uplift on the material bill
- 20.0%
- Waste as a share of what you buy
- 16.7%
Buy 15 sheets, but a quarter of the waste is stock for the next job.
Two hundred linear feet of pine trim
Trim at 2 dollars a linear foot with thirty percent waste for mitres and defects.
You enter
- Material the project needs
- 200 units
- Expected waste
- 30%
- Price per unit
- $2.00
- Share of the waste you will keep and reuse
- 0%
You get
- Extra material the waste adds
- 60.00 units
- Material to buy
- 260.00 units
- Material to buy, rounded up
- 260
- Total purchase cost
- $520.00
- Cost of waste you will not reuse
- $120.00
- Effective cost per unit delivered
- $2.60
- Uplift on the material bill
- 30.0%
- Waste as a share of what you buy
- 23.1%
A 30 percent rate is typical for mitred trim because the offcuts are unusable.
Guides that go with it
How to Avoid Wasting Materials When Making Crafts
Most craft waste is not caused by clumsy hands. It is caused by decisions made before you pick up a tool: buying too much, cutting before measuring, or starting a project with no plan for the offcuts....
The Best Ways to Join Different Craft Materials Together
The brass hinge popped off my walnut box at the worst possible moment: two days before I was supposed to hand it to my sister. I had screwed it straight into end grain, which is basically asking a pie...
Natural vs Synthetic Materials: Which Is Better for Handcrafting?
You are standing in a craft shop aisle, or more likely staring at two browser tabs, and the same question keeps surfacing: do I buy the wool, the linen, the real leather, or do I buy the acrylic yarn,...
Frequently asked questions
How do I calculate material waste?
What is a normal waste percentage for woodworking?
Does waste really cost me anything if I keep the offcuts?
How does waste percentage interact with the saw kerf?
Terms used here
Short, plain-language definitions of the words this calculator uses.