Lead Tape Calculator
Pick a paddle, tap the clock positions where you add lead tape, and see what happens to swing weight, twist weight, balance, power and the sweet spot. Spec sheets tell you where a paddle starts. This tells you where it ends up.
Swing and twist weight are in kg·cm², the units on most spec sheets, with swing weight measured 10 cm from the butt cap. Handle length is butt cap to where the face starts.
Tap a dot to add 1 g. Use the buttons to fine-tune. Total: 6.0 g
Spread along the whole handle. Use − / + on the grip row for other weights.
| Spec | Stock | With tape | Change |
|---|---|---|---|
| Weight | 221.0 g | 227.0 g | +6.0 (+2.7%) |
| Swing weight | 112.0 | 113.0 | +1.0 (+0.9%) |
| Twist weight | 6.20 | 6.69 | +0.49 (+8.0%) |
| Balance point | 247 mm | 246 mm | −1 (−0.2%) |
| Recoil weight | 64.2 | 64.3 | +0.0 (+0.0%) |
| Shot (centre hit) | Ball speed, same swing speed | Ball speed, same effort |
|---|---|---|
| Drive / serve | +0.3% | +0.1% |
| Punch volley | +0.5% | +0.4% |
| Block / reset | +0.9% | +0.9% |
"Same swing speed" is the plow-through you get if you swing exactly as fast as before. "Same effort" includes the swing speed you lose to the extra swing weight. Blocks and resets have no swing, so they only gain.
How the math works
Each piece of tape is treated as a point mass on the edge guard. A mass m at distance r from an axis adds m·r² to the paddle's moment of inertia around that axis (the parallel axis theorem). Swing weight uses an axis 10 cm up from the butt cap, so tape at 12 o'clock, about 31 cm from that axis, adds roughly 1 point per gram. Twist weight uses the paddle's centerline, so tape at 3 and 9, about 9 cm out, adds roughly 0.08 per gram, and tape at 12 adds nothing.
Distance is squared, which is why placement matters more than grams. The same 6 g that adds about 6 points of swing weight at the tip adds almost nothing in the handle. That's why a weighted grip like a Hesacore (12.5 to 16.5 g) makes a paddle heavier on a scale and moves the balance toward your hand while swing weight barely moves.
Power comes from the paddle's effective mass at the contact point, which depends on weight, balance, recoil weight and twist weight. The model is calibrated so your stock paddle reproduces its listed PBCoR at the centre of the face. Swing speed loss uses the measured relationship from Cross & Bower (2006): max swing speed falls with swing weight to the power of about 0.27.
Pop is the part this can't model. The quick, trampoline feel on soft hands comes from the core and face, and lead tape mostly adds mass. Expect tape to make a paddle feel more solid and a touch more muted, not poppier.
Quick placement guide
- 12 o'clock: most swing weight and plow-through per gram, no twist weight.
- 10 and 2: a split of swing weight and twist weight.
- 3 and 9: most twist weight per gram, the biggest sweet spot gain.
- 4 and 8: nearly the same twist weight as 3 and 9 with less swing weight added.
- Weighted grip (Hesacore): heavier on a scale and more head-light, barely heavier in a swing.
The paddle outline is traced from a 3D model of the RPM Jade and scaled to the length and width you enter. Tape is assumed to sit 5 mm inside the edge. Real paddles vary, so measure on a swing weight machine if you need the exact number.