What does the Speed, Distance & Time Calculator do?

Calculate speed, distance or time from the other two. Miles and km with the SDT triangle formula. All calculations are performed in your browser using official UK rates and thresholds.

Is this calculator free to use?

Yes. All calculators on Calks.uk are completely free to use. No account or registration is required. All calculations run in your browser — no data is collected.

Can I use this on my phone?

Yes. All our calculators are fully responsive and work on smartphones, tablets and desktop computers. The interface adapts to your screen size automatically.

Speed, Distance & Time Calculator

Calculate speed, distance or time from the other two. Miles and km with the SDT triangle formula.

Last updated: April 2026 · Source: BBC Bitesize — Speed, distance and time

Distance (miles)

Time

Speed

60.0 mph

96.6 km/h

Distance

150.0 miles

241.4 km

Time

2h 30m

2.50 decimal hrs

Speed = Distance ÷ Time · Distance = Speed × Time · Time = Distance ÷ Speed

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

Speed, distance and time are related by the formula: Speed = Distance ÷ Time. Given any two of the three values, this calculator finds the third. It supports miles per hour (mph), kilometres per hour (km/h) and metres per second (m/s), converting between them automatically.

The calculator is useful for journey planning, running pace calculations and physics problems. For journeys with multiple legs at different speeds, it calculates the correct average speed (total distance ÷ total time), which is not the same as the arithmetic mean of the speeds.

Example: Driving 150 miles in 2 hours 30 minutes

Distance: 150 miles
Time: 2.5 hours
Speed: 150 ÷ 2.5 = 60 mph
60 mph = 96.56 km/h = 26.82 m/s

Source: BBC Bitesize — Speed, distance and time

Frequently Asked Questions

What does the Speed, Distance & Time Calculator do?: Calculate speed, distance or time from the other two. Miles and km with the SDT triangle formula. All calculations are performed in your browser using official UK rates and thresholds.
Is this calculator free to use?: Yes. All calculators on Calks.uk are completely free to use. No account or registration is required. All calculations run in your browser — no data is collected.
Can I use this on my phone?: Yes. All our calculators are fully responsive and work on smartphones, tablets and desktop computers. The interface adapts to your screen size automatically.