Calculate the fuel percentage left in a tank from current volume and capacity, turn a fuel percentage into liters or gallons, or work out fuel blends.

Changing this selection reinterprets entered volumes.

Optional settings

Related Calculators

Fuel Percentage Formula

FP = CFL / MFL × 100

Variables:

  • FP is the Fuel Percentage (%)
  • CFL is the current fuel level (gallons)
  • MFL is the maximum fuel level (gallons)

To calculate tank fuel percentage, divide current fuel volume by usable tank capacity, then multiply by 100. For example, 30 US gal in a 60 US gal usable tank is 50%, with 30 US gal of empty capacity. Gauge height alone is not generally proportional to tank volume. Blend modes instead use (VA×CA+VB×CB)/(VA+VB), assuming additive volumes and volume-based concentrations of the same component.

How to Calculate Fuel Percentage?

The following steps outline how to calculate the Fuel Percentage.

  1. First, determine the current fuel level (gallons). 
  2. Next, determine the maximum fuel level (gallons). 
  3. Next, gather the formula from above = FP = CFL / MFL *100.
  4. Finally, calculate the Fuel Percentage.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

current fuel level (gallons) = 30

maximum usable fuel capacity (US gallons) = 60. Result: 30 / 60 × 100 = 50%.

Frequently Asked Questions

What is the importance of calculating fuel percentage?

Calculating fuel percentage helps in understanding how much fuel is left in the tank in relation to its capacity, allowing for better planning of refueling stops and management of fuel consumption.

Can the fuel percentage formula be used for any type of fuel?

The tank-volume fraction applies when current fuel volume and usable capacity use the same units. Blend calculations require compatible fuels, actual component contents and a consistent volume basis. For an addition target, Vadd=Vexisting×(target−current)/(additive−target). A target already met needs no addition; a different target equal to the added fuel concentration cannot be reached by a finite addition. E85 content varies and should not automatically be entered as 85%.

How can calculating fuel percentage help in improving fuel efficiency?

By regularly monitoring fuel percentage, one can identify patterns in fuel consumption under different driving conditions, leading to adjustments in driving habits that can improve fuel efficiency.