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Speed Distance Time Calculator

Calculate speed, distance or time when you know the other two, in kilometers, miles, meters or nautical miles. Convert between km/h, mph, m/s, ft/s and knots, and see your pace per kilometer and per mile.

Detailed optionsStep-by-step guideWorked examples
Solve for speed, distance or time, and convert speed units.
01 / SPEED · DISTANCE · TIME

Know two values? Find the third.

Choose what you want to calculate, then enter the other two with any units.

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

Speed80 km/h
Speed = 120 km ÷ 1 h 30 min
Average speed: 80 km/h · 49.71 mphDistance: 120 km · 74.565 miPace: 45 s per km · 1 min 12.42 s per mile
02 / SPEED CONVERTER

Convert km/h, mph, m/s, ft/s and knots

Type a speed in any unit to see it in all the others.

100 km/h equals
UnitValue
Kilometers per hour (km/h)100
Miles per hour (mph)62.1371
Meters per second (m/s)27.7778
Feet per second (ft/s)91.1344
Knots (kn)53.9957
YOUR ANIMATED GUIDE

Use the speed, distance and time triangle.

These steps use your current inputs. Choose a step or play the walkthrough.

STEP 1 / 4
Speed
1234

Pick the unknown

Speed, distance and time are linked by one relationship. Know any two and you can find the third.

Speed = Distance ÷ Time
Explore at your own pace

How to use this speed distance time calculator

A speed, distance and time calculator finds any one of the three when you know the other two, and converts between units such as km/h, mph, m/s, feet per second and knots. Use it for journey planning, running pace, physics homework or converting a speed limit. Time can be entered in hours, minutes and seconds, and the answer also shows your pace per kilometer and per mile.

The speed, distance, time formula

The three quantities are linked by one relationship: speed = distance ÷ time. Rearranged, distance = speed × time and time = distance ÷ speed. A common memory aid is the triangle with D on top and S and T underneath: cover the one you want, and the other two show whether to multiply (side by side) or divide (one above the other).

Keep the units consistent

Mixing units is the most common mistake. If speed is in km/h, the time must be in hours and the distance in kilometers. 90 minutes is 1.5 hours, not 1.9. The calculator converts everything to meters and seconds internally, so you can enter distance in miles and see speed in km/h.

Converting speed units

To convert km/h to m/s, divide by 3.6. To convert m/s to km/h, multiply by 3.6. One mile per hour is exactly 1.609344 km/h, and one knot is one nautical mile (1,852 m) per hour, about 1.852 km/h. Use the speed converter below the calculator to convert any speed into all common units at once.

Speed Distance Time formulas, explained

Speed

Speed = Distance ÷ Time

Average speed for a trip = total distance ÷ total time.

Distance

Distance = Speed × Time

Time

Time = Distance ÷ Speed

Convert decimal hours to minutes by multiplying the decimal part by 60.

Speed unit conversion

1 m/s = 3.6 km/h ≈ 2.237 mph ≈ 1.944 kn

1 mph = 1.609344 km/h exactly.

EVERY OPTION, EXPLAINED

Know what goes into your result.

Use this reference to check units, assumptions and advanced settings.

Speed Distance Time calculator input reference
Input or optionWhat it means
Find speed / distance / timeChoose the quantity you want. The other two become inputs.
Distance and distance unitKilometers, miles, meters, feet, yards or nautical miles. When finding distance, the unit sets how the answer is shown.
Speed and speed unitkm/h, mph, m/s, ft/s or knots. When finding speed, the unit sets how the answer is shown.
Hours, minutes, secondsThe travel time. Any combination works, for example 0 h 90 min or 1 h 30 min.
Speed converterType a speed and choose its unit to see the same speed in every other unit.
PUT THE FORMULA TO WORK

Worked examples you can try.

Load an example into the calculator, then change one value to explore.

EXAMPLE 01

Average speed of a trip

120 km in 1 hour 30 minutes: 120 ÷ 1.5 = 80 km/h.

EXAMPLE 02

Marathon finish time

42.195 km at 10 km/h takes 4.2195 hours: 4 h 13 min 10 s.

EXAMPLE 03

Distance covered

Driving at 60 mph for 45 minutes covers 60 × 0.75 = 45 miles.

MAKE THE NUMBERS MAKE SENSE

Common mistakes to avoid

  • Writing 1 hour 30 minutes as 1.3 hours instead of 1.5 hours.
  • Averaging two speeds for a round trip instead of dividing total distance by total time.
  • Mixing kilometers with miles or meters per second with kilometers per hour.
A LITTLE MORE CLARITY

Frequently asked questions

Can this calculator convert speed units?

Yes. The speed converter below the calculator turns any speed into km/h, mph, m/s, ft/s and knots at once.

Which units can I use?

Distance in km, miles, meters, feet, yards or nautical miles; speed in km/h, mph, m/s, ft/s or knots; and time in hours, minutes and seconds.

What is the formula for speed, distance and time?

Speed = distance ÷ time, distance = speed × time, and time = distance ÷ speed. Use consistent units, such as kilometers, hours and km/h.

How do I calculate time from distance and speed?

Divide the distance by the speed. 150 km at 60 km/h takes 150 ÷ 60 = 2.5 hours, which is 2 hours 30 minutes.

How do I convert km/h to m/s?

Divide by 3.6. For example, 72 km/h ÷ 3.6 = 20 m/s. To go from m/s to km/h, multiply by 3.6.

How do I convert mph to km/h?

Multiply by 1.609344. 60 mph is about 96.56 km/h. To convert km/h to mph, divide by 1.609344 (or multiply by about 0.6214).

How do I calculate average speed?

Divide the total distance by the total time, including stops if you want the overall average. Do not simply average the speeds of each leg.

What is a knot?

A knot is one nautical mile per hour. One nautical mile is 1,852 meters, so 1 knot ≈ 1.852 km/h ≈ 1.151 mph. Knots are used in aviation and at sea.

How do I convert minutes to hours for the formula?

Divide minutes by 60. 45 minutes is 0.75 hours. You can also enter hours, minutes and seconds separately in the calculator.

How do I work out running pace?

Pace is time per unit distance, the inverse of speed. At 12 km/h your pace is 60 ÷ 12 = 5 minutes per kilometer. The calculator shows pace per km and per mile.

Methodology & assumptions

Calculations run in your browser using the formulas and assumptions explained on this page. Intermediate values retain full floating-point precision; displayed amounts are rounded. Inputs are converted to SI base units (meters, seconds, meters per second) using exact definitions: 1 mile = 1,609.344 m, 1 foot = 0.3048 m, 1 yard = 0.9144 m, 1 nautical mile = 1,852 m. The result is computed with speed = distance ÷ time and converted back to the selected unit. Results assume a constant (average) speed. Sharing an input link places those inputs in the URL.

Further reading:NIST Guide for the Use of the SI (SP 811)
KEEP EXPLORING

A little more perspective.

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