Help
How to use each calculator.
Every calculator accepts fractions like 3/8, mixed numbers like 5 1/2, and decimals like 5.5. Once you have opened the site, it works offline, and you can add it to your phone's home screen.
Tape measure calculator
Enter a measurement such as 23 17/32, choose add, subtract, multiply, or divide, and enter the second number. Set Round to to the smallest mark on your tape, usually 1/16. Nearest picks the closest mark, Down goes to the mark just below, and Up to the one just above. Choose Don't round to see the exact answer.
The big number is where to mark your tape, the ruler shows that mark in red, and "Off by" shows how far it is from the exact value. Use this result copies the answer into the measurement box so you can keep going, and Undo brings the old number back.
Example: 23 17/32" ÷ 2 is exactly 11 49/64". Rounded to 1/16", mark 11 3/4".
Fraction converter
Type a measurement, choose inches or millimeters, and choose the smallest fraction your tape shows. You get decimal inches, millimeters, centimeters, and the nearest fraction.
Example: 10 mm is 0.3937", which is 3/8" to the nearest 1/16" or 25/64" to the nearest 1/64".
Board feet calculator
Enter thickness and width in inches and length in feet. Board feet equal thickness × width × length ÷ 12. Add the number of boards, and a price per board foot if you want the cost. Use the sizes your lumber seller bills by, which can differ from the finished size. For rough lumber, 4/4 means 1 inch thick.
Example: one board 1" × 6" × 8' is 4 board feet.
Equal spacing calculator
Enter the total length, the width of each item, and how many items. Choose whether you want a gap at both ends or want the items to touch both ends. You get the gap, and where each item starts, measured from the left end, rounded to the mark you choose.
Example: 5 items 1 1/2" wide across 48" with a gap at both ends gives a gap of 6 3/4". The items start at 6 3/4", 15", 23 1/4", 31 1/2", and 39 3/4".
Miter angle calculator
Enter the number of equal sides. The answer is the angle to set your miter saw to, measured from a square cut, and you cut the same angle on both ends of every piece. The corner angle is the angle where two pieces meet.
Example: a four-sided frame uses 45°. A six-sided box uses 30°, and its corners are 120°.