Two-Stroke Fuel Mix Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
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Enter Values
Enter your values and press Calculate to see results.
How to use this calculator
- Enter the litres of petrol and the mix ratio (the oil part of petrol:oil).
- Read the millilitres of oil to add.
How it works
Oil (mL) = petrol (L) × 1000 ÷ ratio. A 50:1 mix of 5 L needs 5000 ÷ 50 = 100 mL of oil.
Worked example
5 L petrol at 50:1. Add 100 mL of two-stroke oil.
Common mistakes
- Guessing the ratio — always use the ratio specified for your engine.
- Mixing too much oil, which fouls plugs and smokes; too little risks seizing.
Frequently asked questions
What ratio should I use?
Follow your engine's manual — common ratios are 50:1, 40:1 and 25:1. When unsure, check the cap or handbook.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.