Gasoline Rotation Schedule Calculator
Enter when you filled your gas cans and how they're stored to get a rotation deadline and days-remaining count so your emergency fuel stays fresh and usable.
For stabilizer dosage, see the Fuel Stabilizer Dosage Calculator.
Calculate your rotation schedule
Tell us about your storage setup to get an accurate shelf-life estimate.
Select a fill date above
Enter your storage details to see rotation schedule.
Tips for success
- Don't skip the stabilizer. Unstabilized E10 gas degrades in as little as 30 days in hot conditions.
- Rotation means burning, not dumping. Use stored gas in your vehicles or equipment first, then refill with fresh fuel and stabilizer.
- Label every container. Use a permanent marker or tape with the fill date on every can.
- Approved containers only. Store in approved metal or HDPE plastic containers; never in unapproved bottles or cardboard.
- Away from ignition sources. Keep containers away from ignition sources and never store inside living spaces.
Even with stabilizer, gasoline doesn't last forever. Old gas causes hard starts, rough running, and gummed carburetors. When in doubt, rotate early; the cost of fresh gas is far less than a carburetor rebuild.
How to use this calculator
Select the date you last filled your fuel containers, enter the total gallons stored, and choose your storage conditions. The calculator estimates your fuel's shelf life and gives you a rotation deadline, the date by which you should use the fuel and refill with fresh gas.
How to properly rotate gasoline
- Oldest fuel first. Use the oldest fuel first in vehicles, generators, and lawn equipment.
- Refill immediately after. After using old fuel, immediately refill containers with fresh gas and add stabilizer.
- Don't over-dilute. Never mix very old fuel with fresh fuel in large quantities; the old gas degrades quality.
- Trust your nose. If fuel smells sour or varnish-like, it has likely degraded; do not use in sensitive equipment.
Common mistakes
- No fill date on the container. Without a label, you'll never know when to rotate.
- Storing in hot outdoor locations. Warm storage cuts shelf life by ~25%; move containers to shade or a cool shed.
- Using E15 for long-term storage. Higher ethanol content accelerates phase separation; use E10 or ethanol-free for stored fuel.
- Forgetting the generator gets old fuel too. Run generators on stored fuel before it degrades; they burn through a can in a few hours.
- Buying 5 cans at once. Stagger fill dates across multiple cans so you're rotating batches, not your entire reserve at once.
FAQ
How long does gasoline last without stabilizer?
Unstabilized E10 gasoline (regular pump gas) typically lasts 3–6 months in a sealed container stored in cool conditions. In heat or with exposure to air, it can degrade in as little as 30 days.
How long does gasoline last with stabilizer?
Standard fuel stabilizers (STA-BIL, etc.) extend shelf life to 12–24 months. Extended-life or fuel-system treatments like PRI-G or STA-BIL 360 can extend shelf life to 2–5 years when applied correctly to fresh fuel.
Is ethanol-free gas worth it for storage?
Yes, ethanol-free gasoline (often labeled "recreational fuel" or available at marina stations) stores significantly longer because ethanol absorbs water and accelerates oxidation. It's worth the extra cost for long-term storage.
Can I use degraded gas in my car?
Diluting moderately old gas (diluted 50/50 with fresh fuel) in a car is usually fine. Severely degraded fuel, varnish-like smell, dark color, should not be used in small engines like generators or chainsaws. Dispose of it at a hazardous waste facility.
How many gallons of gas should I store?
A general rule: store enough to run your generator for 72 hours minimum (typically 15–30 gallons depending on generator size). Larger reserves make sense if you have a vehicle you need to keep fueled during an evacuation.