How the Antifreeze Converter Works
The Antifreeze Converter divides coolant mass by density for the glycol type and concentration. The default 1.115 kg/L fits pure ethylene glycol at 20°C (68°F).
Pick the glycol
Ethylene glycol (EG) and propylene glycol (PG) behave differently.
Pick the mix
Choose the concentration, such as 50/50 by volume.
Enter mass and density
Type the coolant weight and the density from the table.
Read the liters
Compare the volume with the cooling system capacity.
Antifreeze Converter Formula
The antifreeze formula is V = m ÷ ρ(glycol, %). Glycol mixes with water in any ratio and lowers the freezing point.
- ρmix
- Coolant density at the glycol percentage, kg/L
Worked Examples
- 50/50 EG coolant: 10 kg ÷ 1.067 = 9.372 L.
- 8 L engine at 50%: 8 × 0.5 = 4 L of concentrate (4.45 kg EG).
- 40% PG solar loop: 30 kg ÷ 1.033 = 29.04 L.
Antifreeze Converter Conversion Table
A 50/50 ethylene glycol coolant weighs 1.067 kg/L and protects to −37°C (−35°F). The table compares EG and PG mixes by volume.
| Glycol % (v/v) | EG Density (kg/L) | EG Freeze Point | PG Density (kg/L) | PG Freeze Point | EG Liters per 10 kg |
|---|---|---|---|---|---|
| 30% | 1.040 | −15°C (5°F) | 1.026 | −13°C (9°F) | 9.615 |
| 40% | 1.054 | −24°C (−11°F) | 1.033 | −21°C (−6°F) | 9.488 |
| 50% | 1.067 | −37°C (−35°F) | 1.040 | −34°C (−29°F) | 9.372 |
| 60% | 1.080 | −52°C (−62°F) | 1.045 | −48°C (−54°F) | 9.259 |
| 100% | 1.113 | −13°C (9°F) | 1.036 | −59°C (−74°F) | 8.985 |
Pure EG freezes at −13°C; maximum protection with EG comes near 60–68%.
What is an Antifreeze Converter?
An Antifreeze Converter is a calculator that converts engine and HVAC coolant weight into volume using glycol mix density.
Antifreeze is concentrated glycol with corrosion inhibitors. Mixed with water, glycol lowers the freezing point and raises the boiling point of the coolant.
Ethylene glycol is toxic; propylene glycol is far less toxic and suits food plants and potable-adjacent solar and geothermal loops. PG carries about 15% less heat than EG at the same strength.
What are the Uses of an Antifreeze Converter?
There are 4 main uses of an Antifreeze Converter.
Engine coolant top-up
Mechanics convert drum kg into refill liters.
HVAC chilled water
Engineers convert glycol tonnage into loop volume.
Solar thermal loops
Installers mix PG to a target freeze point.
Fleet maintenance
Depots convert bulk tote weights into vehicle fills.