Racquet Swing Weight Calculator

Swing weight depends on where the mass sits relative to the pivot point, not just how much mass there is. This calculator computes it as mass times the squared distance from a standard 10cm pivot to your balance point, plus a rod-approximation term for mass spread along the racquet's length — so a head-heavy racquet with mass far from the pivot produces a much larger swing weight than a head-light racquet of identical static weight, because the distance term is squared.

The calculator treats added weight as a second mass at its own position, so it recomputes the effective balance point as a weighted average of the original weight-at-balance-point and the added weight-at-its-position, then adds the added weight's own mass-times-distance-squared term to the base swing weight. Tape placed near the tip shifts the balance point outward and adds a large swing weight contribution because it sits far from the pivot; the same weight near the handle barely moves either number.

They're two sides of the same swing-weight value: maneuverability starts at 95 for swing weights under 300 kg·cm² and steps down to 20 above 340 kg·cm² using published break points for light, medium, and heavy-feeling frames, while stability is simply 100 minus maneuverability. A racquet can't score high on both — added mass that makes a racquet more stable against off-center hits necessarily makes it slower to swing.

The formula used here is a simplified, calibrated approximation — a real stringing machine like the Babolat RDC measures swing weight with a physical pendulum test, not the parallel-axis-theorem estimate this calculator uses. The absolute number can differ from a professional measurement, but it's internally consistent, so comparing two setups run through this same calculator (say, before and after adding lead tape) is a reliable way to gauge the relative effect of a change.