Car Radiator Sizing Calculator | Find BTU/hr for Your Engine

Car Radiator Sizing Calculator – Prevent Overheating with the Right Cooling Capacity!

Choosing the correct radiator size is critical for engine performance and longevity, hence, we decided to build a free, easy to use Car Radiator Sizing Calculator to help mechanics, racers, and car enthusiasts determine the optimal BTU/hr (British Thermal Units per hour) needed to cool any engine.

Just enter your engine’s horsepower and cooling factor (1.5–2.5) for instant results!

Why Radiator Size Matters:

• Prevents overheating under load
• Improves efficiency in performance engines
• Extends engine life by maintaining ideal temps
• Essential for turbocharged or high-compression builds

FAQs

Q: How does the radiator sizing calculator work?
A: It uses the formula BTU/hr = Horsepower × 2545 × Cooling Factor. The cooling factor adjusts for high-performance engines (1.5–2.5).

Q: What’s the cooling factor?
A: It accounts for extra heat from turbos, superchargers, or aggressive tuning (1.5 = stock, 2.5 = race engine).

Q: Can I use this for diesel engines?
A: Yes! Diesel engines typically need 20–30% more cooling capacity—so, use a higher cooling factor (2.0+).