Calculations4 min read

Metric vs Imperial Asphalt Units

Convert metric and imperial units for asphalt work, including length, area, volume, weight, and density.

Metric vs Imperial Units in Asphalt Work

Most of the world uses metric (SI) units for engineering. The USA, and sometimes the UK and Australia for older projects, uses imperial units. Our calculator supports both systems.

Length & Area Conversions

MetricImperialConversion
1 metre (m)3.2808 feet (ft)1 ft = 0.3048 m
1 centimetre (cm)0.3937 inches (in)1 in = 2.54 cm
1 millimetre (mm)0.03937 inches1 in = 25.4 mm
1 m²10.764 ft²1 ft² = 0.0929 m²
1 km0.6214 miles1 mile = 1.609 km

Volume Conversions

MetricImperialConversion
1 m³35.315 ft³1 ft³ = 0.02832 m³
1 m³1.3080 cubic yards (yd³)1 yd³ = 0.7646 m³
1 litre0.2642 US gallons1 US gal = 3.785 L

Weight Conversions

MetricImperialConversion
1 tonne (metric ton)2,204.6 lbs1 lb = 0.000454 t
1 tonne1.1023 short tons (US)1 short ton = 0.9072 t
1 tonne0.9842 long tons (UK)1 long ton = 1.016 t
1 kg2.2046 lbs1 lb = 0.4536 kg

Note on US tons: In the USA, "ton" usually means a short ton (2,000 lbs), not a metric tonne (2,204.6 lbs). When buying asphalt in the US, confirm whether prices are per short ton or metric tonne — this is a 10% difference.

Density Conversions

kg/m³lb/ft³lb/yd³
2,200137.33,707
2,320144.83,910
2,400149.84,043
2,450152.94,126

Typical HMA: 2,320 kg/m³ = 145 lb/ft³ = 3,915 lb/yd³

Common Asphalt Quantity Conversions

Tonnes to cubic yards:

cubic yards = tonnes ÷ density(t/m³) × 1.308

Example: 10 tonnes of HMA (density 2.32 t/m³):

10 ÷ 2.32 × 1.308 = 5.64 cubic yards

Cubic yards to tonnes:

tonnes = cubic yards × density(t/m³) ÷ 1.308

Quick Thickness Reference

MetricImperial
25 mm1 inch
38 mm1.5 inches
50 mm2 inches
75 mm3 inches
100 mm4 inches

Our calculator handles all conversions automatically. Select "Imperial (ft / in)" to enter feet and inches.

Calculate Asphalt Quantities Instantly

Use our free calculator to get instant bitumen and asphalt quantity estimates for your project.