Mix two-stroke fuel
50:1 on a 5-liter can is not a guess — get the exact oil volume.
Tools used in this guide
The job
Two-stroke engines burn oil mixed into the gasoline; the ratio is written as fuel:oil. Get it wrong lean and the piston scores, wrong rich and the plug fouls.
Fuel plus ratio
Enter the gasoline amount and the ratio's first number (50 for 50:1). The output is the oil to add — the ratio counts fuel alone, not the total.
Worked example
5 L at 50:1 → 100 mL of oil. 1 US gallon at 40:1 → 3.2 fl oz ≈ 95 mL. Measuring cup beats eyeballing every time.
Where it stops
The tool computes oil = fuel ÷ N. Follow the engine manual over convention — some vintage engines want 16:1, modern synthetics tolerate leaner.