Aviation Calculators
Flight time.
Flight time is distance divided by ground speed. Choose what to find, enter the other two values in the units you like, and get the answer in nautical miles, statute miles and kilometres, and in knots, mph and km/h. Runs in your browser; nothing is sent or stored.
Planning aid, not for flight operations
This tool is for study, trip planning and curiosity. It is not approved flight-planning or performance data. For an actual flight, use the aircraft's approved Pilot's Operating Handbook or Aircraft Flight Manual, current weather and charts, and your own judgement as pilot in command. Results can differ from your aircraft's real figures.
Inputs
Result
Fill the form and press Calculate.
Worked example
The FAA handbook's examples, run through this tool. Time: 210 NM at a ground speed of 140 knots is 210 ÷ 140 = 1.5 hours, 1:30. Distance: 1 hour 45 minutes at 120 knots is 120 × 1.75 = 210 NM. Speed: 270 NM in 3 hours is 90 knots, which is 103.6 mph or 166.7 km/h.
How it works
Time = distance ÷ ground speed, distance = ground speed × time and ground speed = distance ÷ time. One knot is one nautical mile per hour. The tool converts everything through kilometres: 1 NM = 1.852 km exactly (about 6,076.1 ft), 1 statute mile = 1.609344 km (5,280 ft), so 1 knot = 1.15078 mph, which the FAA handbook rounds to 1.15.
Use ground speed, not airspeed, because wind changes how fast you cover the ground. The Wind Correction Angle and Ground Speed Calculator finds ground speed from airspeed and wind. Taxi, climb and approach time are not added.
Sources (each opened 2026-10-08): FAA, Pilot's Handbook of Aeronautical Knowledge, Chapter 16: Navigation; Wikipedia, Nautical mile (1,852 m). The statute mile is 5,280 ft by definition (1.609344 km).
FAQ
How do I calculate flight time from distance and speed?
Divide the distance by the ground speed. The FAA handbook's example: 210 NM at 140 knots is 1.5 hours, or 1 hour 30 minutes.
How do I convert knots to mph?
Multiply knots by 1.15 (more exactly 1.15078). The FAA handbook gives this factor from 6,076.1 feet in a nautical mile and 5,280 feet in a statute mile. For example a 20 knot wind is about 23 mph.
Should I use airspeed or ground speed?
Ground speed. Airspeed is speed through the air; a headwind or tailwind changes how fast you cover the ground.
Does the answer include taxi, climb and approach?
No. It is simple distance, speed and time arithmetic at a steady ground speed. Add time for the other phases of flight yourself.
Which time units does it use?
Hours and minutes. When finding time, the result is shown as hours and minutes and as decimal hours.
How far is a nautical mile?
A nautical mile is exactly 1,852 metres, about 1.15 statute miles.