Enter your motor KV, prop pitch, and battery — get estimated top speed, flight time, and thrust-to-weight. Compare motors side by side.
Built for 65–85mm whoops — accuracy calibrated against real whoop builds. Not for 5-inch quads.
Top speed uses a drag-equilibrium model: effective motor RPM under load (not free-spin RPM) sets a pitch-speed ceiling, then aerodynamic frame drag — which grows with the square of velocity — determines where thrust and drag balance. Small whoops spin at a much lower fraction of no-load RPM than 5"+ quads because tiny high-KV motors drop significantly under electrical load, which is why naive pitch×RPM formulas drastically overestimate whoop top speeds.
Flight time is modeled from your battery capacity, an 80% usable discharge window (to protect cell health), and an estimated average current draw based on frame size and motor specs — tuned for aggressive freestyle flying rather than gentle cruising.
Thrust-to-weight uses a bench-fitted power model: thrust = k × watts0.78, fitted from manufacturer test-stand sweeps (Happymodel EX1103 and SE0702), with a per-frame coefficient. The headline thrust number is then clamped to the current your pack can actually source (capacity × C-rating) — the separate bench figure shows what the motors could pull on an unlimited supply. A ratio above 2:1 is generally freestyle-capable; whoops often run lower due to prop and motor constraints at their scale.
| Pitch | Est. Top Speed |
|---|
KV and cell count are linked. KV is how fast the motor spins per volt. More cells means lower KV to keep your prop RPM in a useful range without over-spinning. On whoops that tradeoff is stark: a 1S 65mm build runs 0702 motors at 23,000–30,000KV (race builds push 40K), a 75mm runs 0802 motors at 19,000–32,500KV on 1S, and an 85mm runs 1002–1103 motors at 8,000–23,500KV on 2S. Going too high on KV for your voltage generates heat and shortens motor life.
Stator size sets the torque ceiling. The four-digit stator number tells you everything — "1102" means 11mm diameter, 2mm tall. Wider diameter adds torque and power but also weight. On a whoop that weight penalty is unforgiving: a 0702 is under 2g and suits 65mm indoor builds, while an 0802 gives a 75mm its balance of torque and weight, and a 1002–1103 adds the torque an 85mm needs to swing a 2" prop on 2S.
Match thrust-to-weight to your flying style. Casual freestyle and cruising works well at 2:1–3:1 — a 1S 65mm on 27,000–28,000KV motors lands right about there (~3:1 on the calculator's preset build), enough to climb out of a dive without feeling twitchy. Aggressive freestyle pilots want 4:1 or better for snappy punch-outs, which on a whoop means trimming AUW and running the top of the motor's KV range rather than fitting a bigger stator. A 2S 85mm clears it comfortably. Above 6:1 a whoop gets wheelie-prone and hard to fly smoothly in tight spaces. Whoops sit well below what a 5" freestyle build pulls — prop diameter and 1S/2S voltage cap what the motors can do at this scale.
Don't cheap out on C-rating. An underpowered battery sags badly under load, robbing motor performance and degrading cells quickly. Whoop packs are small enough that C-rating matters more, not less. Manufacturer bench data puts a 0702 at 28,000KV near 4.7A per motor at full throttle — about 19A for all four, so a 1S 300mAh pack at 60C (18A rated) is already marginal and 75C+ is the safer floor. On a 2S 450mAh 85mm build, figure high-20s amps at full punch and 75C+ to keep sag low. Use the battery calculator in the Tools section to check your specific pack against your estimated peak draw.
Pure indoor build. Every gram matters — 0702 motors weigh under 2g each. Prioritize motor weight and efficiency over raw power output.
The Mobula7 class — typically flown 1S or 2S depending on the build and pilot preference. More versatile than 65mm, handles light outdoor wind. A good first whoop for pilots coming off simulators.
85mm whoops typically run 1103 motors on 2S. Bridge between micro whoop and toothpick — more punch than a 75mm, still indoor-capable.
Betaflight PID tunes, rates, and filter settings for 65mm-85mm whoops — stock profiles and RyFly's pilot-tested tunes for BetaFPV, Happymodel, and NewBeeDrone flight controllers.
VIEW TUNE DATABASE →Built by RyFly — FPV pilot & IGOW competitor.
Free browser-based FPV flight simulator with real Betaflight rates, acro and angle mode, a 3-lap race course, and TX16S/EdgeTX radio support.
EXPLORE THE SIMULATOR →RyFly is a competitive FPV freestyle pilot out of Mesa, Arizona — meet the pilot behind QuadMath and see his current competition whoop builds plus his picks for motors, props, batteries, and goggles.
MEET RYFLY & SEE THE GEAR →Available for FPV freestyle filming, event appearances, and social media content — based in Mesa, Arizona and open to travel for the right project.
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