Speed Distance Time
Solve for speed, distance, or time using the SDT formula in any units.
Written by Golam Rabbani, Founder & Lead Engineer
How to use this speed distance time
- Select what you want to solve for: Speed, Distance, or Time.
- Enter values for the two known quantities using the number inputs.
- Choose the unit for each field (km/h, mph, or m/s for speed; km, miles, or m for distance; h, min, or sec for time).
- Press Calculate to see the result along with automatic unit conversions.
- Use Copy to save the result to your clipboard, or Reset to clear all fields.
About this speed distance time
The speed distance time calculator solves for any one of the three variables — speed, distance, or time — when you supply the other two. Select which quantity you want to find, enter the known values, pick your preferred units, and the tool returns the answer with conversions into all supported units.
The tool is built on the standard kinematic relationship: Speed = Distance ÷ Time, rearranged as needed. Internally it converts all inputs to SI base units (metres per second and seconds) before computing, which is why mixing units — say km for distance with minutes for time — works correctly without manual conversion. For distance it supports km, miles, and metres; for time it supports hours, minutes, and seconds; for speed it supports km/h, mph, and m/s.
For example, if you travel 150 km in 1.5 hours, select "Speed", enter 150 km and 1.5 h, then press Calculate. The tool returns 100 km/h, and also shows the equivalent values of 62.1371 mph and 27.7778 m/s. Drivers, cyclists, runners, and students doing physics or maths problems are the primary audience for this tool.
FAQ
- What formula does the speed distance time calculator use?
- It uses Speed = Distance ÷ Time, rearranged to Distance = Speed × Time or Time = Distance ÷ Speed depending on which variable you are solving for. All values are converted to SI units (m/s and seconds) before the calculation so mixed units work correctly.
- Can I mix different units, such as kilometres and minutes?
- Yes. The tool converts every input to metres and seconds internally before computing, so you can freely combine any supported distance unit with any supported time unit and still get an accurate result.
- How accurate are the results?
- Results are calculated in floating-point arithmetic and displayed to four decimal places. For everyday use — travel planning, running pace, school problems — this precision is more than sufficient. Rounding errors in the final digit are possible for very large or very small values.
- What happens if I leave an input blank or enter zero?
- The tool validates inputs before calculating. If a required value is missing, zero, or negative, it displays an error message asking you to enter a valid positive number. No result is shown until the inputs are valid.
- Does this tool store the values I enter?
- No. The speed distance time calculator runs entirely in your browser. Nothing is sent to a server, and all values are cleared when you reset or close the page.
- Is the calculator free to use?
- Yes, it is completely free with no account or signup required.