Construction/ CALCULATOR

Corner check from two sides and their diagonal

Compare a measured diagonal with a square-corner target and estimate the included angle of one triangle.

First side from the shared cornermSame plane and the same corner. Mark stable endpoints.

Second side from the shared cornermNot an opposite wall dimension. Measure to the other marked endpoint.

Distance between the two outer endpointsmThis must form a non-degenerate triangle with the two sides. Repeat measurements.

Diagonal for a 90° included corner

5.000 m

Measured minus square-corner diagonal

0.00 mm

Included angle from the three distances

90.00 °

Included angle minus 90°

0.00 °

Interpretation:This checks one measured triangle, not the whole room or an acceptance tolerance.

One flat triangle with measured straight distances. A positive diagonal difference implies an obtuse included angle; a negative value implies an acute one. Measurement uncertainty is not modelled. No pass/fail tolerance is supplied. A matching diagonal does not prove the whole room is rectangular, opposite sides are parallel, the floor is level or the structure is safe. Verify the other corners and both room diagonals separately.

FROM ESTIMATE TO ACTION

Use the result, not just the number.

Verify the inputs

Measure or document each input. If a value is only an estimate, record its source and test a conservative alternative.

Keep the calculation traceable

Save the input link or copied result together with the date, units and assumptions. A number without its inputs cannot be checked later.

Confirm the decision

Compare the estimate with the related guide, current product data and requirements that apply at your location before buying or building.

Inputs to verify

First side from the shared corner (m): Same plane and the same corner. Mark stable endpoints.
Second side from the shared corner (m): Not an opposite wall dimension. Measure to the other marked endpoint.
Distance between the two outer endpoints (m): This must form a non-degenerate triangle with the two sides. Repeat measurements.

Continue your calculation

Construction

Flooring area and pack quantity

Estimate net floor area, layout allowance and whole packs from effective pack coverage.

Construction

Wallpaper area and roll quantity

Estimate wall area and whole rolls using the product’s effective coverage after pattern matching.

Construction

Skirting length and whole-board estimate

Separate measured perimeter, omitted openings, extra returns, cutting allowance and whole lengths.

Construction

Underlay rolls from complete room-length strips

Compare roll orders for two laying directions instead of assuming all purchased area can be used.

Construction

Identical cut pieces from whole stock lengths

Count repeated equal-length pieces while reserving end trim and one complete cutting kerf for every piece.