Work out road length cost instantly with clear inputs, formula shown and shareable results.
Road cost is driven by area, so length times width times the rate per square metre gives the pavement cost. Drainage, kerbs, signs, markings and safety barriers are added as a percentage because they scale with length rather than area; 10-20 percent is typical for a rural carriageway.
Pavement cost
Cost = length km x 1000 x width x rate per m²
Total
Total = pavement cost x (1 + ancillary percentage)
Cost = length km x 1000 x width x rate per m². Road cost is driven by area, so length times width times the rate per square metre gives the pavement cost.
It is the figure decision makers compare between schemes and against benchmarks. Cost per square metre hides how wide the road is.
This calculator takes 4 inputs: Road length, Carriageway width, Construction rate, Drainage, signs and ancillaries. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.