Don't overpay at the pump. Plug in your rental details and we'll tell you exactly what to put back.

Last updated April 2026

Step 1 — Your Car
Can't find your car? Look it up:
Step 2 — Fuel Levels
Current Level
25% ≈ ¼
Target Level
50% ≈ ½
Target level must be higher than current level.
Step 3 — Get to the Return Location (Optional)
Enter your location and the drop-off point — we'll calculate exactly how much fuel you need for the drive.
Estimated savings
$0
by calculating instead of prepaying or getting hit with a refueling fee
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Pro Tips

Fill Up Away From the Airport

Gas stations within airport grounds charge 2-3x more. Fill up 5-10 minutes away to save.

Photo Your Fuel Gauge at Pickup

Take a timestamped photo of your fuel level when you pick up. This protects you in a dispute.

Prepaid Fuel Is Rarely Worth It

You'd need to return the tank completely empty to break even — which risks running out of gas.

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Why this matters

Most rental companies charge $9–11 per gallon in "refueling service fees" if you return the car with less fuel than you got it. On a half-full tank, that's an easy $60–80 penalty for doing nothing. Prepaid fuel is worse — you pay for a full tank whether you use it or not. FillItRight tells you exactly how many gallons to add at the pump, so you return the car at the level you need and never overpay.

Common questions

How much do rental companies charge for refueling?

Between $9 and $11 per gallon is typical at major US brands (Hertz, Enterprise, Avis, Budget). That's about 3× the retail pump price. On a 15-gallon tank returned half-empty, that's $70+ in fees for fuel you could have added yourself for $25.

Should I take the prepaid fuel option?

Almost never. Prepaid fuel means you pay for a full tank at pickup regardless of how much you use. Unless you plan to return the car empty (which is hard to time perfectly), you're leaving paid-for fuel in the tank. FillItRight's cost comparison shows the break-even point.

How accurate is the fuel gauge on a rental car?

Close but not perfect. Most gauges read within ¼ of a tick, and tanks read slightly lower once the car sits still. FillItRight lets you pick the nearest ⅛ increment so you don't over- or under-fill. If you're unsure, err one increment higher — unused fuel costs less than a refueling fee.

What if I can't find a gas station near the return location?

Use Step 3 to enter your current location and the drop-off address — FillItRight calculates the exact gallons you need for the drive plus the return-level target. That way you can fill up earlier and still return at the right level.

Does the calculator work for international rentals?

Yes. FillItRight auto-detects your currency and unit (liters vs. gallons) and uses regional fuel prices for the cost estimate. Works worldwide.

Gear that pays for itself on rentals

The accessories most renters wish they'd packed. Picked for trips where you're driving someone else's car.

Spare Gas Can
Avoid the $400 tow if you misjudge fuel and run dry on a back road.
~$20-35
USB-C Fast Car Charger
Most rentals have one slow USB port. Multi-port fast charger fixes that.
~$10-20
Phone Car Mount
Hands-free GPS. Holding your phone is illegal in most states ($150+ ticket).
~$15-25
Compact Dashcam
Records pickup walkaround and incidents. Best evidence in damage disputes.
~$30-60

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