Coolant Mix Calculator
Calculate the right antifreeze-to-water ratio for your climate. Get freeze protection, boil protection, and exact fill volumes.
Protection Calculator
Drain & Fill Calculator
If you are draining and refilling (not doing a full flush), calculate how much concentrate vs. water to add back.
Antifreeze Mix Protection Chart
| Coolant % | Freeze Point | Boil Point |
|---|---|---|
| 0% / 100% | 32 F | 212 F |
| 10% / 90% | 26 F | 216 F |
| 20% / 80% | 18 F | 220 F |
| 30% / 70% | 4 F | 226 F |
| 40% / 60% | -12 F | 232 F |
| 50% / 50% | -34 F | 236 F |
| 60% / 40% | -62 F | 240 F |
| 70% / 30% | -84 F | 244 F |
Coolant Types Explained
Brands: Prestone, Peak
Vehicles: Older American vehicles (pre-2000), some Asian
Lifespan: 2 years / 30,000 miles
Brands: Dex-Cool, Havoline
Vehicles: GM (1995+), Saab, VW/Audi
Lifespan: 5 years / 150,000 miles
Brands: Zerex G-05, Motorcraft
Vehicles: Ford, Chrysler, European (Mercedes, BMW, Volvo)
Lifespan: 5 years / 150,000 miles
Brands: Zerex Asian, Toyota SLLC
Vehicles: Toyota, Lexus, Scion, some Honda
Lifespan: 5 years / 150,000 miles
Brands: Genuine Honda, Nissan Blue
Vehicles: Honda, Nissan, Hyundai, Kia, Subaru
Lifespan: 5 years / 100,000 miles
Coolant Maintenance Tips
Never mix types: Mixing IAT (green) with OAT (orange) coolant can cause gelling and clog your cooling system. If unsure, flush the entire system before switching types.
Use distilled water: Tap water contains minerals that cause scale buildup and corrosion. Always use distilled or deionized water when mixing coolant.
Never exceed 70% coolant: Going above a 70/30 coolant-to-water ratio actually reduces heat transfer and can cause overheating. The 50/50 ratio is optimal for most climates.
Check your cap: A faulty radiator cap that cannot maintain pressure will lower the effective boil point. A 15 PSI cap raises the boil point by approximately 45 degrees F.
Test with a refractometer: A coolant refractometer costs $15-$25 and gives an accurate concentration reading. Much better than test strips for verifying your mix.
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