Drone Flight Time Calculator
Realistic flight-time estimate for any multirotor — uses hover efficiency (g/W), pack voltage, ESC efficiency, usable-capacity derating and a flight-style multiplier instead of the naive mAh ÷ current formula.
Most flight-time calculators do the wrong math. They divide battery capacity by current and ignore voltage, hover efficiency, ESC losses and how aggressively you actually fly — the answer is off by 30–50%. This calculator does it properly: it works in energy (watt-hours), uses your motor's thrust efficiency at the hover point, applies a flight-style power multiplier and a usable-capacity derate, and returns a number you can trust before you commit to a build.
curl -X POST https://toolsamurai.com/api/v1/drones-uav/drone-flight-time-calculator \ -H "Authorization: Bearer sk_live_•••••••••••••••" \ -H "Content-Type: application/json" \ -d '{ "auw_grams": 680, "battery_capacity_mah": 1500, "battery_cells_s": "4", "hover_efficiency_g_per_w": 6, "flight_style": "cinematic", "usable_capacity_pct": 80, "esc_efficiency_pct": 92 }'
The method behind the numbers
A drone hovers when total thrust equals all-up weight. The power needed for that thrust depends on the motor + prop's hover efficiency, expressed in grams of thrust per watt (g/W). Divide AUW by efficiency and you have hover power; divide by pack voltage (after ESC losses) and you have hover current.
Pack energy in watt-hours is capacity × nominal voltage (S × 3.7 V for LiPo). Usable energy applies a derate — you can't drain a LiPo flat without damaging it, so flying down to 3.5 V/cell leaves about 80% of nameplate usable. Real-world flight is rarely pure hover, so a style multiplier scales average power above hover: 1.0× for static hover, 1.3× cinematic, 1.8× freestyle, 2.5× racing. Flight time is then usable energy divided by average power, converted to minutes.
The calculator also reports the minimum pack C-rating you need for continuous draw. If your pack can't sustain that current it will sag, the low-voltage cut-off will trip, and the predicted time won't be reached.
See it in practice
680 g AUW, ~6 g/W hover efficiency, freestyle flying.
- auw_grams
- 680
- battery_capacity_mah
- 1500
- battery_cells_s
- 4
- hover_efficiency_g_per_w
- 6
- flight_style
- freestyle
- usable_capacity_pct
- 80
- esc_efficiency_pct
- 92
1600 g AUW, 9 g/W hover, cinematic cruising — the build that's supposed to break 30 min.
- auw_grams
- 1600
- battery_capacity_mah
- 4000
- battery_cells_s
- 6
- hover_efficiency_g_per_w
- 9
- flight_style
- cinematic
- usable_capacity_pct
- 80
- esc_efficiency_pct
- 93
Frequently asked questions
Why is this answer different from other calculators?
Other sites use capacity ÷ current, which silently assumes every cell stays at peak voltage and the motors run at one current forever. Real packs sag, real motors are not 100% efficient, and you fly more than you hover. Working in energy (Wh) and applying a hover-efficiency and style multiplier corrects all three errors.
Where do I get the hover efficiency in g/W?
Motor manufacturers (T-Motor, EMAX, BrotherHobby, iFlight) publish thrust tables for each motor + prop combination. Find the thrust value closest to half your AUW (one motor's hover share on a quad), then divide that thrust by the watts at the same row. Typical bands: tinywhoop 3, 5" race motors 4–5, 5" cinematic 6–7, 7" long-range 8–10, 10" cinelifter 10–12 g/W.
Why does the flight style matter so much?
Throttle scales current non-linearly because thrust grows roughly with the square of throttle. A racing pilot averages 2.5× hover power; a freestyle pilot 1.8×; a cinematic pilot 1.3×. So a 12-minute hover budget collapses to under 5 minutes when you punch it. The multiplier captures this — change it and watch the answer move.
What if my pack can't supply the required C?
Voltage sags below the low-voltage cut-off threshold, the FC throttles you back or auto-lands, and you never see the calculated time. The 'Min Pack C (Continuous)' output tells you the pack rating to look for. Treat manufacturer C-ratings as optimistic — buying 1.3–1.5× the calculated number is sensible.
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