Betaflight Rate Modes — Formulas, Comparison, and Conversion

calendar Jul 13, 2026 · 7 min read · fpv betaflight rates actual-rates kiss-rates quickrates rc-rate expo tuning  ·
Share on: linkedin copy

Betaflight supports four rate mode formulas. They all do the same job — map stick deflection (0 to ±1) to a commanded rotation rate (°/s) — but they parameterize the curve differently. Switching modes changes what the sliders mean, not what the quad feels like if you set equivalent parameters.

Overview

ModeCLI valueParametersBest for
Betaflight (legacy)BETAFLIGHTRC Rate, Super Rate, ExpoDefault; most community presets use this
ActualACTUALCenter Sensitivity, Max Rate, ExpoDirect control over specific feel metrics
KISSKISSRateSingle-knob simplicity
QuickratesQUICKMax RateClosest to linear; cleanest data flights

Switch modes via CLI:

1set rates_type = ACTUAL    # or BETAFLIGHT, RACEFLIGHT, KISS, QUICK
2save

Betaflight remembers your last-used values per mode. Switching modes does not overwrite the other mode's stored values.

Betaflight (Legacy) Rates

Parameters: RC Rate, Super Rate, Expo

Formula:

1stick = |rcCommand|       // 0 to 1
2
3// Expo pre-shaping (reduces center sensitivity):
4if expo > 0:
5    stick = stick × (expo × |stick|³ + (1 − expo))
6
7// Rate with super rate denominator (hockey-stick at extremes):
8output = sign(rcCommand) × stick × rcRate × 200 / (1 − superRate × stick)

The denominator (1 − superRate × stick) is what creates the characteristic "hockey stick" — near center (stick≈0) the effect is minimal, but near full deflection (stick→1) the denominator approaches (1 − superRate), amplifying the output sharply.

ParameterTypical rangeEffect
RC Rate0.8–1.8Scales the entire curve; 1.0 ≈ 200 °/s near center with SR=0
Super Rate0.50–0.75Controls the acceleration at extremes; higher = more hockey-stick
Expo0–0.5Softens center feel; most pilots use 0 or low values

Limitation: RC Rate and Super Rate interact — changing Super Rate also changes the center feel, and vice versa. There is no single parameter that controls only center sensitivity and another that controls only max rate.

Actual Rates

Parameters: Center Sensitivity, Max Rate, Expo

Formula (expo = 0):

1output = sign(rcCommand) × ((max_rate − center) × |rcCommand|² + center × |rcCommand|)

This satisfies two independent constraints simultaneously:

  • Slope at stick = 0: equals center (center sensitivity in °/s per unit)
  • Value at stick = 1: equals max_rate

With expo > 0, the middle portion of the curve is blended toward a sine-shaped curve, creating a gentler mid-range transition.

Advantage: Each parameter controls exactly one thing. You can change center feel without touching the max rate, and vice versa. This makes Actual rates easier to tune to a specific feel.

ParameterEffect
Center SensitivityDegrees/s per stick unit at center. 70–120 is common.
Max RateHard ceiling at full deflection. 600–900 °/s typical freestyle.
Expo0 = pure quadratic curve; higher = softer mid-transition

KISS Rates

Parameters: Rate (single slider)

Formula:

1output = sign(rcCommand) × kissRate × 1998 × |rcCommand| / (1 − kissRate × |rcCommand|)

Structurally identical to the BF legacy formula but with a single combined rate parameter (no separate RC Rate / Super Rate split). Simpler to reason about: one number controls the overall aggressiveness.

  • kissRate = 0.26 → ~700 °/s max, moderate center feel
  • kissRate = 0.32 → ~930 °/s max, more aggressive
  • kissRate < 0.20 → sub-400 °/s max, beginner/cinematic feel

KISS rates are named after the KISS ESC/FC ecosystem where this formula originated. Betaflight's implementation matches the original closely.

Quickrates

Parameters: Max Rate (single slider)

Formula:

1output = sign(rcCommand) × maxRate × |rcCommand|

Perfectly linear. One parameter, one curve. Quickrates is the closest Betaflight gets to a direct "stick position → rotation rate" mapping with no shaping.

When to use:

  • Cinematography and slow-motion builds where you want predictable, linear control
  • Tuning data collection flights where you want the setpoint signal to be clean and linear (makes step response analysis slightly cleaner)
  • New pilots learning acro — linear feel is initially easier to understand

Rate Comparison Chart

Typical settings matched for roughly comparable feel:

{ "type": "line", "data": { "labels": ["0","0.1","0.2","0.3","0.4","0.5","0.6","0.7","0.8","0.9","1.0"], "datasets": [ { "label": "Betaflight (rcRate=1.2, SR=0.70) — max 800°/s", "data": [0,26,56,91,133,185,248,329,436,584,800], "borderColor": "rgba(239,68,68,1)", "backgroundColor": "transparent", "borderWidth": 2.5, "tension": 0.2, "pointRadius": 2 }, { "label": "Actual (Center=100, Max=700, Expo=0)", "data": [0,16,44,84,136,200,276,364,464,576,700], "borderColor": "rgba(34,197,94,1)", "backgroundColor": "transparent", "borderWidth": 2.5, "tension": 0.2, "pointRadius": 2 }, { "label": "KISS (rate=0.26) — max 702°/s", "data": [0,53,110,169,232,299,369,445,525,610,702], "borderColor": "rgba(99,102,241,1)", "backgroundColor": "transparent", "borderWidth": 2, "tension": 0.2, "pointRadius": 2 }, { "label": "Quickrates (max=700) — linear", "data": [0,70,140,210,280,350,420,490,560,630,700], "borderColor": "rgba(249,115,22,1)", "backgroundColor": "transparent", "borderWidth": 2, "borderDash": [5,3], "tension": 0, "pointRadius": 2 } ] }, "options": { "responsive": true, "interaction": { "mode": "index", "intersect": false }, "plugins": { "title": { "display": true, "text": "Rate mode comparison — commanded °/s vs stick deflection (0 to 1)" }, "legend": { "position": "bottom" } }, "scales": { "x": { "title": { "display": true, "text": "Stick deflection (0 = center, 1 = full throw)" } }, "y": { "min": 0, "max": 850, "title": { "display": true, "text": "Commanded rotation rate (°/s)" } } } } }

Key observations:

  • BF (red): starts shallow (low center sensitivity at these settings) but accelerates hard at extremes — the hockey stick is visible above 0.7 stick
  • Actual (green): defined quadratic — clean, predictable slope from center to max
  • KISS (purple): similar shape to BF but parameterized with one number; mid-stick feel slightly more linear than BF
  • Quickrates (orange dashed): truly linear — equal spacing between all points

BF ↔ Actual Conversion

The two curves have different shapes, so a perfect conversion does not exist. These formulas give a close starting point:

BF → Actual

1Actual.center    ≈ BF.rcRate × 200
2Actual.max_rate  = read from BF configurator (full-stick output value)
3Actual.expo      ≈ BF.superRate / 2.0   (rough starting point — tune by feel)

Example: BF rcRate=1.5, superRate=0.70, expo=0

  • Actual.center = 1.5 × 200 = 300
  • Read configurator: max output ≈ 900°/s → Actual.max_rate = 900
  • Actual.expo = 0.70 / 2.0 = 0.35

Actual → BF

1BF.rcRate      ≈ Actual.center / 200
2BF.superRate   ≈ Actual.expo × 2.0   (starting point)

After computing, open the configurator and visually compare the two curves on the Rate graph. Adjust superRate until the full-stick output matches your desired max rate. The curves will not be identical — choose the one that matches the feel you want at mid-stick.

Equivalent Feel — Example Presets

FeelBetaflightActualKISS
Freestyle mediumRC=1.4, SR=0.70, E=0Center=100, Max=750, E=0.30Rate=0.28
Racing / sharpRC=1.8, SR=0.75, E=0Center=140, Max=900, E=0.25Rate=0.32
Smooth / cinematicRC=0.8, SR=0.40, E=0.20Center=50, Max=350, E=0.40Rate=0.15
2" ripperRC=1.2, SR=0.65, E=0Center=90, Max=650, E=0.30Rate=0.24

These are starting points — adjust to taste. The configurator Rate graph updates live, so compare visually rather than trusting the numbers exactly.

Which Mode Should I Use?

Use Betaflight (legacy) if you're loading community presets or following a tune guide that specifies RC Rate and Super Rate values. The vast majority of published presets assume this mode.

Use Actual if you want to independently control "how sharp is center" vs "how fast does full stick go". Particularly useful when copying the feel of a previous build to a new one with different motor/prop — you can match center sensitivity and max rate independently.

Use KISS if you prefer one slider, tend to fly from muscle memory alone, and don't want to think about the interaction between RC Rate and Super Rate.

Use Quickrates for cinematography or for tuning data collection flights (linear setpoint = cleanest step response data).

All four modes can produce an identical real-world flying feel if parameterized correctly. Mode choice is a matter of how you prefer to think about and adjust the curve — not which one is "better".

Related Snippets