High and hot means a longer runway.
See how density altitude stretches both your takeoff and landing roll, and flattens your climb. Enter pressure altitude and temperature, or get density altitude from the density altitude calculator. This is an interactive version of the FAA Koch chart, extended to landing distance.
High density altitude stretches both your takeoff roll and your landing rollout, and flattens your climb. Enter pressure altitude and temperature to see the penalty — or get density altitude straight from the density altitude calculator. (This is an interactive version of the FAA Koch chart.)
Educational estimates only — not for flight planning, dispatch, or weight-and-balance. Always fly the numbers in your POH and current official weather.
Runway view — the bars show your takeoff and landing rolls at density altitude; the dashed line marks the sea-level figure.
A lot, and non-linearly. At ~6,000 ft pressure altitude and 100 °F (~9,800 ft density altitude) takeoff distance increases about 230% over a sea-level standard day — a 1,000 ft ground roll becomes ~3,300 ft (matches the FAA Koch chart). Confirm against your POH and runway available.
Roughly 3.5% per 1,000 ft of density altitude. The cause is true airspeed: at altitude your TAS at touchdown is higher for the same indicated approach speed, so you carry more energy and roll farther. At ~9,800 ft DA a 1,200 ft sea-level landing becomes ~1,650 ft.
The Koch chart is an FAA-recommended graphical tool that estimates how much takeoff distance increases and rate of climb decreases as pressure altitude and temperature rise. This calculator is an interactive version of it, extended to also estimate landing distance. It is an approximation for when POH data isn't handy — always defer to your POH.
Roughly 7–8% per 1,000 ft of density altitude for a normally-aspirated airplane. At ~9,800 ft DA a 500 fpm sea-level climb drops to ~120 fpm. Climb is usually what you feel first on a hot, high day.