2-Stroke Mix Chart: Every Ratio in Gallons and Litres
Published July 26, 2026 · 5 min read
A 2-stroke mix chart turns a ratio into a number you can actually pour. Every row on this page comes from one piece of arithmetic, oil = fuel ÷ ratio, applied to a US gallon of 128 fluid ounces and a litre of 1000 millilitres. Nothing here is typed by hand, which is why these tables, the calculator and the printable mix charts can never disagree with each other.
Whether your machine says 2-cycle, 2-stroke or two-stroke on the cover, and whether you call the fuel premix or mixed gas, the tables below are the same.
Quick reference: every ratio at a glance
| Ratio | Oil per US gallon | Oil per litre | Oil per 2 gal | Oil per 5 gal | Oil per 5 L |
|---|---|---|---|---|---|
| 20:1 | 6.4 oz | 50 ml | 12.8 oz | 32 oz | 250 ml |
| 25:1 | 5.12 oz | 40 ml | 10.24 oz | 25.6 oz | 200 ml |
| 32:1 | 4 oz | 31.25 ml | 8 oz | 20 oz | 156.25 ml |
| 40:1 | 3.2 oz | 25 ml | 6.4 oz | 16 oz | 125 ml |
| 50:1 | 2.56 oz | 20 ml | 5.12 oz | 12.8 oz | 100 ml |
| 100:1 | 1.28 oz | 10 ml | 2.56 oz | 6.4 oz | 50 ml |
2-stroke mix chart: gallons to ounces
Find your gas amount down the left and read across to your ratio. All figures are US fluid ounces of 2-stroke oil.
| Gallons of gas | 20:1 | 25:1 | 32:1 | 40:1 | 50:1 | 100:1 |
|---|---|---|---|---|---|---|
| 0.5 | 3.2 | 2.56 | 2 | 1.6 | 1.28 | 0.64 |
| 1 | 6.4 | 5.12 | 4 | 3.2 | 2.56 | 1.28 |
| 1.5 | 9.6 | 7.68 | 6 | 4.8 | 3.84 | 1.92 |
| 2 | 12.8 | 10.24 | 8 | 6.4 | 5.12 | 2.56 |
| 2.5 | 16 | 12.8 | 10 | 8 | 6.4 | 3.2 |
| 3 | 19.2 | 15.36 | 12 | 9.6 | 7.68 | 3.84 |
| 4 | 25.6 | 20.48 | 16 | 12.8 | 10.24 | 5.12 |
| 5 | 32 | 25.6 | 20 | 16 | 12.8 | 6.4 |
| 6 | 38.4 | 30.72 | 24 | 19.2 | 15.36 | 7.68 |
2-stroke mix chart: litres to millilitres
Same chart in metric. All figures are millilitres of oil.
| Litres of gas | 20:1 | 25:1 | 32:1 | 40:1 | 50:1 | 100:1 |
|---|---|---|---|---|---|---|
| 1 | 50 | 40 | 31.25 | 25 | 20 | 10 |
| 2 | 100 | 80 | 62.5 | 50 | 40 | 20 |
| 3 | 150 | 120 | 93.75 | 75 | 60 | 30 |
| 4 | 200 | 160 | 125 | 100 | 80 | 40 |
| 5 | 250 | 200 | 156.25 | 125 | 100 | 50 |
| 10 | 500 | 400 | 312.5 | 250 | 200 | 100 |
| 15 | 750 | 600 | 468.75 | 375 | 300 | 150 |
| 20 | 1,000 | 800 | 625 | 500 | 400 | 200 |
| 25 | 1,250 | 1,000 | 781.25 | 625 | 500 | 250 |
Need a size that is not on the chart, or a ratio that is not a preset? The calculator handles any amount in either unit system, and it works in reverse when you know how much oil you have:
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Which row do you need?
The ratio comes from your machine, not from a general rule. In order of authority: the decal on or beside the fuel cap, then the owner’s manual, then the manufacturer’s published specification for that model and year. Only when all three are gone should you fall back on the table below.
| Equipment | Usual ratio | Notes |
|---|---|---|
| Modern chainsaw, trimmer, blower | 50:1 | Stihl, Husqvarna, Echo, Shindaiwa, Makita current ranges |
| Equipment from the 1970s to 1990s | 40:1 | Also many budget tools sold today |
| Two-stroke dirt bike, kart | 40:1 to 32:1 | The manual gives a range; the rider narrows it |
| Vintage saws, older Lawn-Boy mowers | 32:1 | Designed around mineral oils |
| Older outboards, some break-in schedules | 25:1 | Use a marine TC-W3 oil |
| Oils explicitly rated for it | 100:1 | Never assume it; check the bottle |
Working it out without a chart
The whole chart is one division, so you can reproduce any row in your head:
- Ounces of oil per US gallon = 128 ÷ ratio. At 40:1 that is 128 ÷ 40 = 3.2 oz.
- Millilitres of oil per litre = 1000 ÷ ratio. At 40:1 that is 1000 ÷ 40 = 25 ml.
Then multiply by however much fuel you are mixing. A 5-gallon can at 40:1 is 3.2 × 5 = 16 oz, which happens to be exactly one US pint, one of the few conversions worth memorising.
Three mistakes a chart does not protect you from
Reading the wrong gallon. These tables use the US gallon of 128 fl oz. An imperial gallon is larger, so a chart written against it gives a different number for the same ratio. If your manual is British, Canadian or Australian, work in litres and skip the ambiguity.
Trusting the bottle instead of the chart. The 2.6 oz single-use bottles are dosed for one gallon at 50:1. The moment your machine calls for 40:1, or your can holds two gallons, that bottle no longer matches. Emptying one 2.6 oz bottle into a 2-gallon can is roughly a 100:1 mix, and it is one of the most common causes of a scored piston in handheld equipment.
Mixing in the tank. Oil poured straight into a machine’s fuel tank does not disperse. Measure the oil into an empty, approved fuel can, add the gas second so pouring stirs it, seal the can and shake it before you fill.
Print it for the shed
The mix charts page prints clean, with the navigation and everything else stripped out, sized to pin above a workbench. It is faster than a phone when your hands are dirty.
For the ratio pages with their own full tables and context, see 50:1, 40:1, 32:1, 25:1 and 100:1. For the step-by-step routine, read how to mix 2-stroke fuel; if the two spellings are still bothering you, 2-cycle vs 2-stroke settles it; and when you are choosing what goes in the bottle, TC-W3 vs JASO FD explains which rating your engine needs. Reading a number off a chart is only half the job: the measuring tools guide covers the cups and bottles that let you hit it, and the outboard fuel mix guide covers the one machine class where the ratio depends on the model year.
Common questions
[01] What is the 2-stroke mix chart for 50:1?
At 50:1 you add 2.56 fl oz of 2-stroke oil per US gallon of gas, which is 5.12 oz for 2 gallons, 12.8 oz for 5 gallons, and 20 ml per litre in metric. The rule behind every row is the same: 128 divided by the ratio gives the ounces of oil per gallon.
[02] How much oil per gallon for a 2-cycle engine?
It depends on the ratio your engine specifies. At 50:1 it is 2.56 oz per gallon, at 40:1 it is 3.2 oz, at 32:1 it is 4 oz, and at 25:1 it is 5.12 oz. Check the decal on the fuel cap or the owner's manual for the ratio, then read the row.
[03] Is a 2-stroke mix chart the same for 2-cycle engines?
Yes. '2-stroke' and '2-cycle' are two names for the same engine type, so any mix chart works for both. You will also see it written as 'two-stroke' and the fuel called 'premix'. The arithmetic does not change with the spelling.
[04] Does the chart change for imperial gallons?
Yes, and it is a common mistake. These charts use the US gallon of 128 fluid ounces. An imperial gallon is larger, so the same ratio needs more oil per gallon. If you are working from a UK or Canadian manual, use the metric litres column instead to avoid the confusion entirely.
[05] What ratio should I use if I cannot find the spec?
Choose the richer ratio of the two you are weighing up. Too much oil causes smoke, a fouled plug and a sooty exhaust, all of which clean up. Too little oil removes the lubricating film and scores the piston, which does not. On unmarked air-cooled equipment, 40:1 is the safer default than 50:1.
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