Car & Vehicle

Fuel Tank Range Calculator

How far a tank of fuel goes, with a reserve you choose rather than one this page invents.

7 inputs Free, no sign-up

Your figures

Use the figure you actually get, not the showroom one. City driving commonly lands 20-30% below a rated number, and the mileage calculator works yours out from a tank.

Tank capacity is in the handbook. It differs between variants of the same model, so it is not something this page can fill in for you.

Litres you would rather not use. Leave blank to see the range to a dry tank, which is a figure to know rather than a plan to follow.

The price you actually paid. Pump prices move daily and differ by several rupees between states, so the round number here is a placeholder, not a quote.

Try an example

Result

Your result

Enter your figures and the result appears here.

Estimates only. Rates, fees and specifications change. Confirm against the official source before you rely on a figure — see our disclaimer.

About this calculator

Range is fuel multiplied by mileage, and both halves are yours. A tank capacity differs between variants of the same model and a mileage differs between two drivers of the same car, so neither is filled in here.

What this page adds is the reserve. Running a tank dry is bad for the fuel pump, which is cooled by the fuel around it, and worse for the evening. Say how much you would rather keep and the range is quoted to that point.

How to use this calculator

  1. Enter the mileage you actually get on the kind of driving ahead.
  2. Enter the fuel on board — the tank capacity for a full tank, or your best estimate of what is in it.
  3. Set a reserve you would rather not use. Leave it blank to see the range to a dry tank.
  4. Read the range, in kilometres or miles.

Tank capacity is in the handbook. It is not something this page can look up, and a figure taken from a review of a different variant would be wrong.

The formula

Usable fuel = Fuel on board - Reserve
Range       = Usable fuel x Mileage

Both figures are shown when a reserve is set: the range to the reserve, which is the one to plan on, and the range to empty, which is a fact rather than a plan.

SymbolMeaningUnit
Fuel on board Tank capacity or what is in it L or gal
Reserve What you would rather not use L
Mileage What the vehicle returns km/L or mpg

Worked example

A 42-litre tank at 18 km/L, keeping 5 litres back:

Usable = 42 - 5   = 37 litres
Range  = 37 x 18  = 666 km
To dry = 42 x 18  = 756 km

Ninety kilometres of difference, which on a highway is the gap between a comfortable stop and an anxious one.

Notes and limits

  • The car's own range estimate is based on recent consumption and updates as you drive. It is often more accurate than this for the next hour and less accurate for the next tank.
  • The low-fuel warning is not a fixed number of litres on every vehicle and should not be treated as a known reserve.
  • Highway range is usually well above city range. Use the mileage that matches the road ahead, not your overall average.
  • Air conditioning, a full load and a roof box all shorten the range, and none of them is in the mileage figure unless it was measured with them.
  • For a two-wheeler, the reserve tap holds a genuinely small amount. Treat the figure with the reserve as the real range.

What this calculation assumes

  • Mileage holds for the whole tank.
  • Tank capacity and reserve are figures you entered. Neither is assumed.

Frequently asked questions

How far can I go on a full tank?

Multiply the tank capacity by your mileage. A 42-litre tank at 18 km/L gives 756 km to a dry tank, or 666 km if you keep 5 litres in hand.

How much fuel should I keep in reserve?

That is your call and this page will not choose for you. Enough to reach a station you know about is the usual rule; on a highway with long gaps between pumps, more.

Is it bad to run the tank very low?

It is not ideal. In most cars the fuel pump sits in the tank and is cooled by the fuel around it, so running consistently near empty gives it a harder life. Sediment at the bottom of an older tank is a second reason.

Why does the car's range display disagree with this?

The car estimates from recent consumption, so it reacts to how you have been driving in the last few minutes. This uses the figure you entered, which is a longer-run average. Neither is wrong; they are answering slightly different questions.

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