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Chainsaw Fuel Mix Calculator

Quick Answer Most modern chainsaws use a 50:1 fuel mix ratio (2.6 fl oz of oil per gallon of gas). Older chainsaws may require 40:1 or 32:1. Always check your owner's manual for the exact ratio.

Chainsaw Fuel Mix Calculator

50:1
40:1
32:1
25:1
Custom Ratio: :1

Oil Needed

You Need
2.6
fl oz
for 1 gallon at 50:1 ratio
Milliliters
77
US Fluid Ounces
2.6
Liters
0.077

Chainsaw Fuel Ratios by Brand

Stihl Chainsaws

50:1

All Stihl chainsaws manufactured after 2002 use 50:1 ratio. Pre-2002 models may use 40:1.

→ Stihl Calculator

Husqvarna Chainsaws

50:1

Modern Husqvarna chainsaws use 50:1 ratio with high-quality synthetic oil.

→ Husqvarna Calculator

Echo Chainsaws

50:1

Echo chainsaws use 50:1 ratio with Echo Power Blend or equivalent 2-stroke oil.

→ Echo Calculator

Makita Chainsaws

50:1

Makita 2-stroke chainsaws use 50:1 ratio with JASO FD certified oil.

Poulan/Craftsman

40:1

Many Poulan and Craftsman chainsaws use 40:1 ratio. Check your manual.

Vintage Chainsaws

32:1 or 25:1

Older chainsaws (pre-1990s) typically require richer 32:1 or 25:1 ratios.

Chainsaw Fuel Ratio Reference

Ratio Oil per Gallon Oil per Liter Typical Chainsaws
50:1 2.6 fl oz (77 mL) 20 mL Stihl, Husqvarna, Echo (post-2002)
40:1 3.2 fl oz (95 mL) 25 mL Poulan, older Stihl, some Craftsman
32:1 4.0 fl oz (118 mL) 31 mL Vintage chainsaws (1980s-1990s)
25:1 5.1 fl oz (151 mL) 40 mL Very old chainsaws (1970s-1980s)

Always Check Your Owner's Manual

Using the wrong fuel ratio can severely damage your chainsaw. Too little oil (leaner than recommended) causes inadequate lubrication and can seize the engine. Too much oil (richer than recommended) causes excessive smoke, carbon buildup, and fouled spark plugs.

When in doubt: It's safer to use slightly more oil than too little. If you can't find your manual, contact the manufacturer or search for your model number online.

What Oil Should I Use in My Chainsaw?

Use high-quality 2-stroke oil that meets one of these standards:

Brands like Stihl HP Ultra, Husqvarna XP+, Echo Power Blend, and Amsoil Saber are all excellent choices. Never use regular motor oil (10W-30, 5W-20, etc.) as it's not designed to burn in 2-stroke engines.

→ Complete Oil Selection Guide

Chainsaw Fuel Mix FAQs

What fuel mix ratio do chainsaws use?
Most modern chainsaws use a 50:1 fuel mix ratio (2.6 fl oz of oil per gallon of gas). Older chainsaws from the 1990s and earlier may require 40:1 or 32:1. Always check your owner's manual for the exact ratio your specific model requires.
What ratio does Stihl chainsaw use?
Stihl chainsaws manufactured after 2002 use a 50:1 fuel mix ratio. Older Stihl models (pre-2002) may require 40:1. Stihl recommends using Stihl HP Ultra or HP Super synthetic oil. If you're unsure, check the label on your chainsaw or contact your dealer.
What ratio does Husqvarna chainsaw use?
Modern Husqvarna chainsaws use a 50:1 fuel mix ratio. Husqvarna recommends using their XP+ synthetic 2-stroke oil or any high-quality oil meeting JASO FD or ISO-L-EGD standards. This ratio applies to both consumer and professional models.
How much oil do I mix with 1 gallon of gas for a chainsaw?
For modern chainsaws using 50:1 ratio, mix 2.6 fl oz (77 mL) of 2-stroke oil with 1 gallon of gasoline. For older chainsaws using 40:1, mix 3.2 fl oz per gallon. For 32:1, use 4.0 fl oz per gallon.
Can I use regular motor oil in my chainsaw?
No, never use regular motor oil (10W-30, 5W-20, etc.) in a chainsaw. You must use 2-stroke specific oil that is designed to be mixed with gasoline and burned in 2-stroke engines. Regular motor oil will cause severe engine damage, excessive smoke, and carbon buildup.
What happens if I use the wrong ratio?
Using too little oil (leaner mix) causes inadequate lubrication, overheating, and can seize your engine—an expensive repair. Using too much oil (richer mix) causes excessive smoke, spark plug fouling, carbon deposits, and reduced power. Always use the manufacturer's recommended ratio.
How do I mix fuel for my chainsaw?
  1. Pour gasoline into an approved fuel container (not directly into chainsaw)
  2. Measure the correct amount of 2-stroke oil using the calculator above
  3. Add oil to gasoline (not gas to oil)
  4. Cap container and shake vigorously for 30 seconds
  5. Use within 30 days for best performance
→ Detailed Mixing Guide
Can I buy pre-mixed chainsaw fuel?
Yes! Pre-mixed fuel (like Stihl MotoMix, Husqvarna XP Pre-Mix, or TruFuel) is available and convenient. It's ethanol-free, has a longer shelf life (2+ years unopened), and comes pre-mixed at the correct ratio. It's more expensive per gallon but great for occasional use or long-term storage.

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