Reach Advantage Calculator
Calculate reach advantage between two fighters based on arm span, height, and stance.
Useful for MMA and boxing analysis.
What is reach and why it matters:
Reach (or arm span) is measured fingertip to fingertip with arms extended horizontally. In combat sports, reach determines who can strike first from distance. A fighter with longer reach can land jabs and front kicks while staying outside their opponent’s effective range.
Reach vs. height ratio:
Most people have an arm span roughly equal to their height (a 1:1 ratio, called the “Vitruvian” proportion). Fighters with a positive ape index (reach greater than height) have a natural distance advantage.
Ape Index = Reach - Height
| Ape Index | Classification | Advantage |
|---|---|---|
| < -5 cm | Short reach | Must close distance aggressively |
| -5 to 0 cm | Average | Neutral |
| 0 to +5 cm | Above average | Slight jab range advantage |
| +5 to +10 cm | Long reach | Strong distance control |
| > +10 cm | Exceptional | Elite-level reach (like Jon Jones at +26 cm) |
Effective striking range formula:
Jab range = (Reach / 2) × 0.95 + Shoulder width × 0.3
Cross range = (Reach / 2) × 1.05 + Shoulder width × 0.5
These account for shoulder rotation. A cross extends further than a jab because the rear shoulder drives forward.
Reach advantage between two fighters:
Raw reach advantage = Fighter A reach - Fighter B reach
Effective advantage = Raw advantage × Stance modifier
| Stance Matchup | Modifier | Reasoning |
|---|---|---|
| Orthodox vs Orthodox | 1.0 | Standard |
| Southpaw vs Southpaw | 1.0 | Standard |
| Orthodox vs Southpaw | 0.85 | Open stance reduces pure reach advantage |
| Switch-hitter | 0.90 | Can neutralize by matching stance |
Example calculation:
Fighter A: 188 cm tall, 198 cm reach (Orthodox) Fighter B: 183 cm tall, 185 cm reach (Orthodox)
- Raw advantage: 198 - 185 = 13 cm
- Effective advantage: 13 × 1.0 = 13 cm
- Fighter A ape index: 198 - 188 = +10 cm (exceptional)
- Fighter B ape index: 185 - 183 = +2 cm (average)
Tactical implications by advantage size:
- 0–5 cm: Minimal difference. Technique and timing matter more than reach.
- 5–10 cm: Noticeable advantage. Longer fighter can maintain distance with jabs.
- 10–15 cm: Significant. Shorter fighter must use head movement and angles to close distance.
- 15+ cm: Dominant. Shorter fighter typically needs wrestling or clinch work to negate reach.