Woodworking Unit Converter
Plans in millimetres, tape in inches? Convert both ways and get the answer the way you'll use it — 19 mm comes back as 3/4" (and how far off that is), and 1 5/16" comes back as 33.34 mm.
Enter a value above to convert it.
Couldn't read that value — try a plain number, a fraction like 3/4, or a mixed number like 12 3/8.
Units sorted. Now lay out the cuts.
CUTLIST.io bundles all five shop calculators with the cut list optimizer — Rip First, Crosscut First, Max Yield, or Smart Stack — so you buy the right amount of material and waste less of it.
Get the whole suite of toolsInches, millimetres and the fraction in between
An inch is exactly 25.4 mm, so the math is simple — the useful part is turning the decimal back into something you can find on a tape. 19 mm is 0.748", which is 3/4" to within four thousandths. Pick the fraction your tape (or your tolerance) can handle: 1/16" for rough work, 1/32" for joinery, 1/64" if you're reading a rule under a lamp.
Common plywood thicknesses
| Sold as | Actual (in) | mm |
|---|---|---|
| 1/4" | ~7/32 (0.21) | 5.5 |
| 1/2" | 15/32 (0.47) | 12 |
| 3/4" | 23/32 (0.72) | 18 |
| 12 mm | 15/32 | 12 |
| 18 mm | 45/64 (0.71) | 18 |
More free shop calculators
Board Foot Calculator
Board feet and lumber cost for a list of boards.
Tape Measure Calculator
Add, subtract, multiply and divide tape measurements, fractions included.
Circle Glue-Up Calculator
Board lengths for a glue-up you'll cut into a circle.
Quick Fill Calculator
How many of one part fit on a sheet, kerf included.
Questions
Why does 3/4" plywood measure 23/32"?
Sheet goods are sold by nominal thickness; the real panel is slightly thinner after sanding. Measure your actual sheet before cutting dados — or let the optimizer use the real number.
Can I type a fraction as the input?
Yes — 3/4, 1 5/16, 0.75 and 12 3/8 are all read the same way the CUTLIST.io app reads dimensions.
What does the (+0.004) mean?
How far the nearest fraction is from the exact conversion. If it's more than your tolerance, step up to 1/32" or 1/64".