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.

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.

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.

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.

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.

2-Stroke Mix Chart: Every Ratio in Gallons and Litres

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:

Fuel → oil Oil → fuel

Amount of fuel

Equipment (optional)

Mix ratio

Custom ratio (X : 1)

Add this much oil

12.8 oz

≈ 378.54 ml

Add 12.8 oz of 2-stroke oil to 5 gal of gas at a 50:1 ratio.

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.