# Gas Calculator (Trip Gas Cost)

URL: https://speedycalculator.com/calculators/everyday-life/gas/
Last updated: 2026-10-25

> The gas calculator estimates how much gas a trip needs and what it costs for popular cars or your own fuel economy, adjusted for city or highway driving, and splits the cost between passengers.

## Inputs

- Car
- Fuel economy (if Other) (mpg (US), mpg (UK), km/L)
- Trip type
- Distance (mi, km, m, nmi)
- Gas price (/US gal, /L, /UK gal)
- People sharing

## Results

- Fuel economy used
- Gas used
- Cost of the trip
- Cost per person

## Formula

```
Fuel economy = car rating × trip factor (city 0.85, highway 1.15)
Gas used = distance ÷ fuel economy
Cost = gas used × price; per person = cost ÷ people
```

## Explanation

A car's combined fuel economy rating blends city and highway driving. City traffic with stops and starts usually gives 10–20% worse economy, and steady highway driving 10–20% better. Pick a model or enter your own figure.

### How to use the Gas Calculator

- **Car**
- **Fuel economy (if Other)**
- **Trip type**
- **Distance**
- **Gas price**
- **People sharing**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Choose a car (or "Other" and enter its mpg), the type of trip, distance, gas price and the number of people sharing.

### Tips

- Use your own measured figures – fuel economy, speed and prices vary a lot with driving style, traffic, load and season.
- Pick the unit in each field's menu (miles or kilometres, mpg or L/100 km); the calculator converts everything for you.
- Fill up to the brim twice and divide the distance by the fuel added to measure real fuel economy.
- For vehicle modifications, treat results as a starting point and confirm with the parts maker or a professional mechanic.

### Common mistakes to avoid

- Mixing US and imperial (UK) gallons – a UK gallon is about 20% bigger.
- Using the advertised fuel economy instead of real-world figures.
- Forgetting tolls, parking and wear and tear when comparing driving with public transport.

### Inputs explained

FieldWhat to enterCarChoose one: Ford F-150 (≈ 20 mpg), Chevrolet Silverado (≈ 19 mpg), Toyota Camry (≈ 32 mpg), Honda Civic (≈ 35 mpg) …Fuel economy (if Other)Units: mpg (US), mpg (UK), km/LTrip typeChoose one: Mixed, Mostly city, Mostly highwayDistanceUnits: mi, km, m, nmiGas priceUnits: /US gal, /L, /UK galPeople sharingA number

### What each result means

- **Gas used** = [Distance]÷[Fuel economy used]
- **Cost of the trip** = [Gas used]×[Gas price]
- **Cost per person** = [Cost of the trip]÷[People sharing]

### Example values

How the main result changes when **Fuel economy** changes and everything else stays at the example values above:

Fuel economy (if Other) (mpg (US))Cost of the trip12.521.8718.7521.872521.8731.2521.8737.521.875021.87

## Worked example

Inputs — Car: Toyota Camry (≈ 32 mpg); Fuel economy (if Other): 25 mpg (US); Trip type: Mixed; Distance: 200 mi; Gas price: $3.5 /US gal; People sharing: 1.

Results — Fuel economy used = 32 mpg (US); Gas used = 6.25 US gal; **Cost of the trip = $21.87**; Cost per person = $21.87.

## FAQ

**How much gas will a 200-mile trip use?**
At 32 mpg about 6.25 gallons – roughly $22 at $3.50/gal.

**Why is my car's real mpg lower than the rating?**
Short trips, cold weather, aggressive driving, heavy loads and under-inflated tyres all reduce economy.

**How accurate are the model figures?**
They are approximate EPA combined ratings for recent models; enter your own measured mpg for best accuracy.

**What formula does the Gas Calculator use?**
Fuel economy = car rating × trip factor (city 0.85, highway 1.15).


## Sources

- [U.S. DOE / EPA – fueleconomy.gov](https://www.fueleconomy.gov/)