Speed, Distance, Time Calculator

This professional-grade calculator solves for any one of speed, distance, or time when the other two are known. It’s designed for students, engineers, athletes, sailors, and anyone who needs fast, accurate answers with clean unit conversions and WCAG 2.1 AA accessibility.

Interactive Calculator

Choose variable to solve for

Results

Solved value —
Input recap —

Data Source and Methodology

Authoritative Data Source: OpenStax — University Physics Volume 1 (2016), Chapter 2 “Kinematics.” Direct link. Secondary reference for units and symbols: NIST Special Publication 811 (2008 release), “Guide for the Use of the International System of Units (SI).” Direct link.

Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.

The Formula Explained

$v = \dfrac{d}{t}$

$d = v \cdot t$

$t = \dfrac{d}{v}$

Where $v$ is speed, $d$ is distance, and $t$ is time. Units must be consistent (e.g., meters, seconds).

Glossary of Variables

Speed (v)
Average rate of change of distance with respect to time. Units: m/s, km/h, mph, or knots.
Distance (d)
Total path length traveled. Units: m, km, mi, nmi.
Time (t)
Elapsed duration. Units: s, min, h.
Conversions
1 mi = 1609.344 m; 1 nmi = 1852 m; 1 h = 3600 s; 1 km/h = 0.2777778 m/s; 1 mph ≈ 0.44704 m/s; 1 kt ≈ 0.514444 m/s.

How It Works: A Step-by-Step Example

Scenario: A car travels 120 km in 1.5 hours. What is the average speed?

  1. Choose “Solve for Speed.”
  2. Enter distance: 120 and select km.
  3. Enter time: 1.5 and select hours.
  4. Apply $v = \dfrac{d}{t}$: $v = \dfrac{120\ \text{km}}{1.5\ \text{h}} = 80\ \text{km/h}$.
  5. Converted to m/s: $80\ \text{km/h} = 80 \times \dfrac{1000}{3600} \approx 22.222\ \text{m/s}$.

Frequently Asked Questions (FAQ)

Is this calculator for average or instantaneous speed?

It computes average speed over a specified interval, based on total distance and total time.

Can I enter zero values?

You may enter zero for distance (resulting speed or time will reflect that). Time and speed must be greater than zero when used in a denominator.

Which conversions are supported?

Speed: m/s, km/h, mph, knots. Distance: m, km, miles, nautical miles. Time: seconds, minutes, hours.

What about direction?

This tool computes speed (a scalar). If you need velocity (a vector), direction is required and not part of this calculator.

How are results rounded?

Values are displayed with sensible precision (up to 6 significant digits) to balance readability and accuracy.

Can I share a prefilled calculation?

Yes. The URL updates with your inputs. Use the Share button to copy a link that opens with your values preloaded.

Is it suitable for maritime/aviation use?

Yes, knots and nautical miles are supported. Always follow operational guidance for safety-critical calculations.

Tool developed by Ugo Candido. Content verified by CalcDomain Editorial Team.
Last reviewed for accuracy on: .