2-Stroke Pre-Mix Oil Calculator
Calculate the precise amount of 2-stroke oil to mix with your gasoline for any popular ratio from 16:1 to 100:1 — chainsaws, dirt bikes, outboards, snowmobiles, karts and trimmers.
2-Stroke Pre-Mix Calculator
Choose what you want to find. The other two values become your inputs.
Mix this much oil
13.0 oz of oil
Pour 13.0 oz of oil into an empty 5 US-gallon fuel can first, then add the gasoline.
Common 2-Stroke Mix Ratios
Reference chart for every popular 2-stroke ratio in both US and metric units.
| Mix ratio | Oz of oil per US gallon | ml per liter | Typical use |
|---|---|---|---|
| 16:1 | 8.00 | 62.5 | Vintage two-stroke spec; some older outboards |
| 20:1 | 6.40 | 50.0 | Older chainsaws and trimmers, some kart engines |
| 24:1 | 5.30 | 41.7 | Some racing snowmobiles and karts |
| 25:1 | 5.10 | 40.0 | Older Yamaha / Mercury outboards, vintage dirt bikes |
| 32:1 | 4.00 | 31.3 | Common Stihl, Husqvarna, Echo handheld spec |
| 40:1 | 3.20 | 25.0 | Husqvarna, Poulan, Weed Eater, many trimmers |
| 50:1 | 2.60 | 20.0 | Most modern handheld OPE, snowmobiles, dirt bikes, outboards |
| 60:1 | 2.10 | 16.7 | Some modern dirt bikes and karts |
| 80:1 | 1.60 | 12.5 | AMSOIL SABER Pro recommended for trimmers / handheld OPE |
| 100:1 | 1.28 | 10.0 | AMSOIL SABER Pro maximum lean ratio for warranty-protected handheld OPE |
Why the right 2-stroke ratio matters
Two-stroke engines burn their oil along with the fuel — a "total-loss" lubrication system. Mix too lean (not enough oil) and the piston, rings and bearings starve, scuff and seize. Mix too rich (too much oil) and you get plug fouling, exhaust-port carbon buildup, smoke and reduced power. Modern OEM mix ratios are calibrated to a specific oil quality, so substituting a low-grade oil at the same ratio invites the same wear that running too lean would cause.
One bottle for every ratio
AMSOIL SABER® Professional Synthetic 2-Stroke Oil is engineered to lubricate at any ratio from 32:1 to 100:1 in air-cooled handheld 2-stroke equipment, eliminating the need to stock multiple bottles for chainsaws, trimmers, blowers and brushcutters with different OEM specs. AMSOIL specifically tested SABER Professional at 100:1 in real-world OPE for warranty protection.
Fresh fuel matters as much as the right ratio
Pump gasoline containing E10 ethanol absorbs moisture from the air, which separates from the gas, sinks to the bottom of the can, and starves the carb when the engine demands fuel. Pre-mix made with E10 typically goes off in 30 days. Two ways to extend shelf life: (1) use ethanol-free recreation fuel where available, or (2) treat the pre-mix with AMSOIL Quickshot®, which stabilizes ethanol fuel for up to 6 months and keeps moisture in solution.
Two-Stroke Pre-Mix FAQs
Why does AMSOIL SABER Professional work from 100:1 all the way down to 32:1?
SABER Pro is a clean-burning, ashless synthetic 2-stroke oil engineered to deliver full film strength at very lean ratios. AMSOIL specifically tested it at 100:1 in handheld OPE for warranty protection, but it also handles richer 50:1 / 40:1 / 32:1 specs without coking, ringland deposits or smoke. One product on the shelf covers every saw, trimmer, blower and brushcutter you own.
Should I use 50:1 or 100:1 in my chainsaw?
Run the OEM-specified ratio if you are still under warranty. Once that no longer applies, AMSOIL SABER Professional is approved by AMSOIL for use as lean as 100:1 in air-cooled handheld 2-stroke equipment, which dramatically reduces oil consumption, smoke and exhaust deposits. For water-cooled outboards, snowmobiles and dirt bikes, run the OEM ratio (typically 50:1).
How do I convert ounces per gallon to milliliters per liter?
Divide ounces per US gallon by 0.128 to get milliliters per liter. Example: 50:1 is 2.6 oz per US gallon, which is 20 ml per liter. The chart above shows both columns side by side for convenience.
Does ethanol in pump gas matter for 2-stroke pre-mix?
Yes. Ethanol pulls moisture out of the air, so pre-mix made with E10 has a shorter shelf life — typically 30 days in a vented can. Use ethanol-free recreation fuel where available, or treat your mix with AMSOIL Quickshot to stabilize the fuel for up to 6 months.
Can I use 4-stroke motor oil in a 2-stroke engine in a pinch?
No. 4-stroke oils contain detergent, anti-wear and ash-forming additives that will plug the exhaust port, foul the spark plug and seize the rings on a 2-stroke engine. Always use a true 2-stroke pre-mix oil designed for total-loss lubrication.
How do I measure oil accurately at 100:1?
At 100:1 you only need 1.28 oz of oil per gallon of gas — much less than a typical bottle pour. Use the AMSOIL SABER Professional bottle's built-in measure (graduated to 1, 2, 4 and 6 oz) or a syringe-style measuring cup. Round up rather than down — a slightly rich mix never hurt a saw.
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Independent AMSOIL Dealer #1858536. This calculator is for reference only — always defer to your equipment manufacturer's specifications. Inputs stay in your browser; nothing is submitted, stored or logged.