Flight Time Calculator
Calculate great-circle distance and flight time between two coordinates.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Estimate great-circle distance, airborne time plus a fixed 30-minute allowance, local arrival time and a simple distance-based CO₂ estimate. The speed field is airborne speed; the 30-minute allowance is added separately. Actual schedules depend on routing, weather, aircraft and operations. Arrival time is shown as decimal hours, and the CO₂ figure is not an airline-specific estimate.
Worked example
calculated with the default values below
Origin latitude 40.71 ° · Origin longitude -74.01 ° · Destination latitude 51.51 ° · Destination longitude -0.13 ° · Average airborne speed 850 km/h · UTC offset at destination relative to origin 5 h · Departure time (local) 9 h Great-circle distance 5,570 km · Great-circle distance 3,461 mi · Estimated airborne time plus 30-min allowance 7.05 h · Estimated destination arrival (decimal hours) 21.05 h · Distance-based CO₂ estimate per passenger 501 kg
General background references
Disclaimer
These calculators give general estimates. Sizing, pricing, availability and standards vary by brand, retailer and country, so treat the output as a starting point and confirm it against the seller's or authority's own figures.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
a = sin²(Δφ ÷ 2) + cos φ1 × cos φ2 × sin²(Δλ ÷ 2); d = 2R × atan2(√a, √(1−a)); T = d ÷ v + 0.5
- φ1
- origin latitude
- φ2
- destination latitude
- Δφ
- latitude difference (rad)
- Δλ
- longitude difference (rad)
- R
- Earth radius, 6371 km
- v
- cruise speed (km/h)
- a
- haversine intermediate
- d
- great-circle distance (km)
- T
- total flight time (h)
Coordinates are converted from degrees to radians; the haversine value is clamped for floating-point safety. Estimated time adds a fixed 0.5 h after distance ÷ airborne speed. Arrival uses a manually entered time-zone shift, displays clock time only, and does not model calendar dates or daylight-saving rules. CO₂ is a simple distance proxy.
Frequently asked questions
What does the estimated flight time include?
The model divides great-circle distance by the entered average airborne speed, then adds a fixed 0.5 hour. This is not an airline schedule or block-time estimate. Arrival uses your manually entered destination offset and shows clock time only; it does not calculate a date or daylight-saving rules. Per-passenger CO₂ is a simple distance proxy, not airline-specific.