Calculating your oil to add is straightforward once you know the Two-Stroke Fuel Mix formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Two-Stroke Fuel Mix Calculator.
What is Two-Stroke Fuel Mix?
The Two-Stroke Fuel Mix calculation tells you your oil to add from a few simple inputs. The figure you are solving for here is the oil to add.
The Two-Stroke Fuel Mix formula
The core formula is:
Oil to add = Petrol quantity × 1000 ÷ Mix ratio (Petrol quantity : oil)Here is what each input means:
- Petrol quantity — a value measured in litres. Example: 5 litres.
- Mix ratio (fuel : oil) — a number. Example: 50.
How to calculate it step by step
- Write down the petrol quantity (for example, 5 litres).
- Write down the mix ratio (fuel : oil) (for example, 50).
- Apply the formula above to get your oil to add.
- Double-check the result with the Two-Stroke Fuel Mix Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Petrol quantity | 5 litres |
| Mix ratio (fuel : oil) | 50 |
| Oil to add | 100.0 |
With petrol quantity of 5 litres and mix ratio (fuel : oil) of 50, the oil to add works out to 100.0.
Example 2
With petrol quantity of 10 litres and mix ratio (fuel : oil) of 50, the oil to add works out to 200.0.
| Result | Value |
|---|---|
| Oil to add | 200.0 |
Example 3
With petrol quantity of 2.5 litres and mix ratio (fuel : oil) of 50, the oil to add works out to 50.0.
| Result | Value |
|---|---|
| Oil to add | 50.0 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the Two-Stroke Fuel Mix Calculator does it instantly, for free, with the formula and a worked example built in.
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