Bitumen
How to Convert Bitumen Litres to Tonnes (and Back)
Bitumen is bought by weight but often specified for application by volume — here is the conversion done properly, with density accounted for.
This conversion trips people up because it looks like it should be a fixed multiplier, the way converting metres to feet is — but it isn’t, because it depends on density, and bitumen density varies by grade and temperature.
Litres to tonnes
Tonnes = (Litres × Density in kg/m³) ÷ 1,000,000
Because 1,000 litres = 1m³, and 1,000,000 grams = 1 tonne.
Tonnes to litres
Litres = (Tonnes × 1,000,000) ÷ Density in kg/m³
This is the same relationship rearranged.
Ready-reference table at common densities
| Litres | At 1000 kg/m³ | At 1030 kg/m³ | At 1050 kg/m³ |
|---|---|---|---|
| 1,000 L | 1.000 tonnes | 1.030 tonnes | 1.050 tonnes |
| 5,000 L | 5.000 tonnes | 5.150 tonnes | 5.250 tonnes |
| 10,000 L | 10.000 tonnes | 10.300 tonnes | 10.500 tonnes |
| 20,000 L | 20.000 tonnes | 20.600 tonnes | 21.000 tonnes |
The density you use has to match the temperature you’re measuring at
A tanker delivery note showing volume at 150°C will convert to a different tonnage than the same volume measured at 15°C, because hot bitumen is less dense. Always confirm whether a quoted volume is a "hot volume" or a "15°C reference volume" before converting — this single detail causes more invoicing disputes than any other bitumen calculation error.
Why this conversion matters commercially
Bitumen is almost always bought and sold by weight (tonnes), but application rates for spray work (tack coats, prime coats, surface dressing) are specified by volume (litres per m²). If you’re pricing a spray job, you need to convert your calculated litre requirement into tonnes to actually place the order — and get an accurate cost, since bitumen is priced per tonne.
Example: a surface dressing job needs 1.2 L/m² over 8,000m², which is 9,600 litres. At a working density of 1030 kg/m³, that converts to (9,600 × 1030) ÷ 1,000,000 = 9.888 tonnes to order — not 9.6, which is what you’d get if you skipped the density conversion entirely and assumed 1 litre = 1 kg.
The calculator handles this conversion automatically — try it here