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Geometry & Setout
Setting-out maths for the field, in sections.
Dimensional maths in any mix of units. Type 5' 3-1/2" + 2' 7", 1.2m - 300 or 12' x 10' and read the answer in millimetres, metres and feet-inches. Multiplying two lengths gives an area, three a volume. Press Enter to keep a line on the tape.
Tape
Enter any 3 values (at least one side). Sides a, b, c sit opposite angles A, B, C. Angles in degrees.
Quick sine, cosine, tangent and reciprocals for any angle.
About this tool
Geometry & Setout is a set of construction-master style calculators for setting out in the field — feet-inch-fraction and metric dimensions, square checks, trig and triangle solving, circles and arcs, stair and rafter geometry, and compound mitres. Choose a section and the maths updates as you type.
How to use it
- Pick a section from the tabs, e.g. Setout, Stairs or Rafters.
- Enter your known dimensions in feet-inches or metric.
- Read the calculated results, angles or cutting lines instantly.
- Switch sections for a different calculation without losing your inputs.
FAQ
Is it free?
Yes — every section here is free, with no limits.
Is this a substitute for engineering sign-off?
No — it's a fast field calculator; structural decisions still need an engineer where required.
Does it upload anything?
No — all maths runs locally in your browser.
What sections does it cover?
Setout dimensions, square check, trig and triangles, circles and arcs, stairs, rafters, compound mitres and volumes.
Estimates only — verify against your spec and standards. ← all tools