SlopeCalc
Calculator

One vertical unit per N horizontal units

Slope ratio calculator

Choose uphill or downhill and convert an exact 1:N ratio to decimal slope, percent, per mille, and approximate angle.

Private browser calculation

Choose the known representation

Stays on this page

Calculation mode

Known values and units

N is the positive horizontal part of a 1:N vertical-to-horizontal ratio.

SlopeCalc handles ideal geometric slope only. It does not determine permissible grades, building-code compliance, accessibility, drainage, traction, structural design, or measurement uncertainty.