What this calculator shows
The time, speed, and distance relationship lets you find one quantity when the other two are known. This calculator can solve for distance, ground speed, or time en route. It uses nautical miles, knots, and hours.
For navigation planning, use ground speed rather than true airspeed when solving for time or distance over the ground. Wind changes ground speed.
How to use the calculator
Choose the quantity to solve for, then enter the other two values. Time is entered as decimal hours. For example, 1.5 hr is one hour and thirty minutes. Inputs update the answer immediately and are reflected in the URL.
How the calculation works
The basic relationship is:
distance = speed x time
Rearrange it to solve for the other quantities:
speed = distance / time
time = distance / speed
The units must match: knots are nautical miles per hour, so multiplying knots by hours gives nautical miles.
Example calculation
For a 120 kt ground speed over 1.5 hr:
- Distance:
120 x 1.5 = 180 NM. - The same relationship can solve for time. At
120 kt, a180 NMleg takes180 / 120 = 1.5 hr.
The calculator displays time as decimal hours and also gives a hours-and-minutes interpretation.
Assumptions and limitations
The calculation assumes the entered speed is constant over the entered period. It does not calculate wind, account for climb or descent, or predict a route. Use representative ground speed for the part of the flight being estimated.
Check units before using a result. Entering statute miles where nautical miles are intended, or entering minutes as decimal hours, changes the answer.
Sources and methodology
This tool applies the distance, speed, and time relationship using aviation units. The FAA Pilot's Handbook of Aeronautical Knowledge covers flight planning and navigation concepts. Actual route, wind, and performance planning require current conditions and aircraft documentation.
Related tools and resources
Flight planning
About this site
Related glossary terms
Glossary
Squawk 7700 is the transponder code used to indicate an emergency when no more specific code or instruction applies.
Glossary
Above ground level, or AGL, is an altitude measured from the surface directly below an aircraft. Learn how it differs from MSL.
Glossary
Automatic terminal information service, or ATIS, is a recorded airport broadcast of current weather and operational information.
Directory resources
Directory
FBO directory at selected US airports
Sourced FBO listings at selected airports, with questions to confirm directly with each operator.
Directory
A&P and IA aircraft mechanic directory
How to compare aircraft mechanic and repair-station listings, confirm credentials, and evaluate maintenance services.