# Speed Calculator

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

> The speed calculator finds average speed from distance and time, and compares how much time you save or lose at a different speed.

## Inputs

- Distance (mi, km, m, nmi)
- Time (min, h, s)
- Compare with speed (mph, km/h, m/s, knots)

## Results

- Average speed
- Pace
- Time at comparison speed
- Time difference

## Formula

```
Average speed = distance ÷ time
Time at another speed = distance ÷ new speed
```

## Explanation

Average speed is total distance divided by total time, including stops. Driving faster saves less time than people expect: on a 30-mile trip, going 70 instead of 60 mph saves only about 4 minutes.

### How to use the Speed Calculator

- **Distance**
- **Time**
- **Compare with speed**
- Every result field is editable: type into **Average speed** and **Time** plus every other field update to match.

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

### How it works

Enter the distance and the time it took. Optionally enter another speed to compare the travel time. Type a speed into the result to find the time.

### 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 enterDistanceUnits: mi, km, m, nmiTimeUnits: min, h, sCompare with speedUnits: mph, km/h, m/s, knots

### What each result means

- **Average speed** = [Distance]÷[Time]
- **Pace** = [Time]÷([Distance]÷1609.344)÷60
- **Time at comparison speed** = [Distance]÷[Compare with speed]÷60
- **Time difference** = [Time]÷60 - [Time at comparison speed]

### Example values

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

Time (min)Average speed (mph)1512022.580306037.54845406030

## Worked example

Inputs — Distance: 30 mi; Time: 30 min; Compare with speed: 70 mph.

Results — **Average speed = 60 mph**; Pace = 1 min/mi; Time at comparison speed = 25.7 min; Time difference = 4.3 min.

## FAQ

**How do I calculate average speed?**
Divide the total distance by the total time: 30 miles in 30 minutes is 60 mph.

**How do I convert mph to km/h?**
Multiply by 1.609344.

**Does driving faster save much time?**
Less than you might think – 10 mph faster on a 30-mile trip saves about 4 minutes but uses noticeably more fuel.

**What formula does the Speed Calculator use?**
Average speed = distance ÷ time.