Estimate average kick impact force, effective striking mass, foot speed, or contact time with a transparent impulse-momentum model.
Kick Force Formula or Method
The model assumes the entered effective striking mass loses the entered forward speed during contact. Average force equals that momentum change divided by the contact interval.
How the Calculation Works
The requested output field is hidden, disabled, cleared, and made non-required. Only source values needed for the selected relationship remain available.
How to Use This Calculator
- Select the result you want in the Solve for menu.
- Enter only the visible source values and their explicit units.
- Select Calculate and review the primary answer, supporting values, and substituted steps.
- Use Reset before starting a different fighter, bout, or scenario.
Worked Example
An effective striking mass of 12 kg moving at 10 m/s over 30 ms produces an average-force estimate of 4,000 N, or about 899.2 lbf.
Input and Result Guide
| Item | How to use it |
|---|---|
| Effective striking mass | The dynamically coupled portion of the leg and body, not total body weight. |
| Impact speed | Foot or shin speed immediately before contact, entered in m/s or mph. |
| Contact time | Duration of force application in milliseconds. |
| Average force | An impulse-based mean; it is not the instantaneous peak. |
| Technique | Roundhouse, front, side, and other kicks can couple mass and direction differently. |
Interpreting the Result
Compare results only when the ruleset, units, tracking definitions, and sample boundaries are consistent.
Assumptions and Limitations
This is a simplified physics estimate, not a force-plate measurement. It omits peak loading, target and limb compliance, rebound, rotation, angle, balance, technique, sensor response, and injury risk. Never strike a person to test a calculation.
Common Questions
Why did an input disappear when I changed Solve for?
The hidden field is the requested output. Enter the remaining visible values and the calculator will solve for that target.
Will my last successful calculation be restored?
Yes. The calculator saves enabled source values and the successful result in this browser. Reset clears that saved state.
Sources
OpenStax, University Physics Volume 1, impulse and momentum; Bureau International des Poids et Mesures, The International System of Units, 9th edition.