Disclaimer

Every calculator on this site gives an estimate from a standard formula and the numbers you enter. Results are for planning, learning and checking your own work.

• A result is only as good as its inputs and the formula’s assumptions. Real fabrics, machines, belts, products and measurements vary.
• Machine and workshop sums (pulley speeds, belt lengths, gear ratios) are arithmetic, not ratings. Check the maker’s limits for speed, load and fixings before you run or hang anything.
• Coursework answers follow the most common textbook conventions, which each page states. Check the convention your course or exam uses.
• The site does not give medical, legal, tax or financial advice.

If you think a result is wrong, please tell us through the contact page. See how the calculators work for rounding rules and limits.