The Toyota Prius gas tank size does not remain the same throughout the years, having undergone major changes since as early as 2002.
So if you are unsure what yours is, my insightful chart and guidelines can lend you some help. Keep scrolling.
How Many Gallons Are In A Prius?
The Prius tank size has changed in different model years. The latest models from 2016 to 2023 share the same 11.3-gal tank, while models from 2003-2015 boast a tank of 11.9 gallons.
To learn how many gallons are in your Prius, check out the following chart:
Year | Gas Tank Sizes (Imp.) |
2023 | 11.3 Gallons |
2022 | 11.3 Gallons |
2021-2016 | 11.3 Gallons |
2015 – 2003 | 11.9 Gallons |
2001-2002 | 11.8 Gallons |
How to Check The Toyota Prius Gas Tank Size
If you forget how many gallons of gas your Prius holds, either dig up the owner’s manual or use a measuring tape to calculate the height, width, and length by yourself. Another option is to drive until the tank empties and refill it.
Method 1. Measure your gas tank.
- Grab a calculator and tape measure and prepare yourself for some basic Math:
- Measure the tank’s height, length, and width separately
- Multiply them together
- Divide the number by 231 (cubic inches converted to gallons) to yield how many gallons your Prius holds.

Method 2. Find the manual
Take out the manual, then check for the drivetrain or any relevant keyphrase (ex: gas tank capacity).
The information is important, so there is no way the manual leaves it out; it should only take minutes to find the page you need.
Method 3. Drive until the tank is empty, then refill it
If none of the options above are available, you are left with the last resort: keep driving until the fuel gauge reaches “E.” Then go to a gas station and fill the tank to get rough estimations of its capacity.
This method can be quite spontaneous and not 100% perfect (there might still be slight miscalculations). But even so, the number will not stray too far from the tank’s actual capacity, so no need to worry!
Does Gas Tank Size Matter? Is It Better To Have A Big Gas Tank?

The matter is still in debate. Large gas tanks have huge advantages: they allow longer trips and reduce the need for frequent refueling, which can be convenient for long road stretches or remote regions.
However, the extra weight of large tanks may add to the car’s overall load and increase fuel consumption. Here is where smaller tanks like Prius shine: the advantages of their lightweight designs foster better fuel economy, better handling, and more responsive brakes.
At the end of the day, the ultimate choice is up to your driving style, types of terrains, and preferences.
What Is The Gas Mileage of Toyota Prius?
Toyota Prius impresses everyone with its mileage figures: 58 miles per gallon (city), 53 MPG (highway), and 56 MPG (highway and city combined). With these fuel ratings, Prius easily finds its way among the best and most economical production vehicles.
How Often Should You Fill Your Gas Tank?
Refill the tank whenever it is between 1/4 and 1/2 full. Any number lower than 1/4 is risky; you will never know when the gas suddenly acts up or runs out sooner than expected.
Conclusion
Prius’s lightweight tanks partly contribute to the car’s impressive handling and braking response.
However, there comes a small price: it needs frequent refueling. Always monitor the oil level, and immediately fill your tank whenever it stoops below 1/2 full.
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