Car Battery CCA Calculator
Find the minimum Cold Cranking Amps your battery needs based on engine size, fuel type, and climate.
| Group | CCA Range | Common Fitments |
|---|---|---|
| 51R | 410–500 CCA | Honda CR-V, Fit, Accord (some) |
| 35 | 550–640 CCA | Honda Civic/Accord, Toyota Camry/Corolla, Subaru |
| 75 | 550–625 CCA | GM compact cars |
| 24/24F | 550–750 CCA | Honda, Acura, Lexus, Toyota trucks |
| 34 | 600–800 CCA | Dodge Ram, Chrysler 300, Jeep |
| H6 (48) | 650–800 CCA | Chevy, GMC, Chrysler |
| 65 | 650–850 CCA | Ford F-150, Mustang, Mercury |
| 94R (H7) | 730–900 CCA | BMW, Audi, VW, Mercedes |
Highlighted rows indicate groups whose CCA range covers your recommended value. Always verify fitment in your owner's manual.
What is CCA?
Cold Cranking Amps (CCA) is the number of amps a 12-volt battery can deliver at 0°F (-18°C) for 30 seconds while maintaining at least 7.2 volts. It measures how well a battery performs in cold conditions — exactly when an engine needs maximum current to turn over. A higher CCA rating means more starting power in cold weather.
Why Diesel Engines Need More CCA
Diesel engines have much higher compression ratios (16:1 to 23:1 versus 8:1 to 12:1 for gasoline engines). This means the starter motor must work significantly harder to turn the engine over. Additionally, diesel engines rely entirely on compression heat for ignition — there are no spark plugs — so the engine must be cranked long enough for the cylinders to reach ignition temperature. Both factors demand roughly twice the CCA of a comparable gasoline engine.
How to Read a Battery Label
Battery labels show several ratings: CCA (cold cranking amps at 0°F), CA or MCA (cranking amps at 32°F — always higher than CCA, which can be misleading), RC (reserve capacity in minutes), and Ah (amp-hours). Always compare CCA to CCA when shopping. The group number (like "Group 35") refers to the physical size and terminal placement — it must match your vehicle's battery tray and hold-down.
Reserve Capacity (RC) Explained
Reserve Capacity is the number of minutes a fully charged battery at 80°F can deliver 25 amps before dropping below 10.5 volts. A higher RC means you can run accessories (radio, lights, phone charger) longer if the alternator fails, or recover better from an accidental overnight parasitic drain. For overlanding or off-grid driving, prioritize RC alongside CCA.