Stringing machine
Sets the reference tension while the racquet is being strung.
Best for: the starting string jobCompare your own baseline
Racquet String Tension Checker
Compare a current reading with your fresh-string baseline and preferred floor. See the change in lbs, kg, and percent—then decide from your own range.
Measure With String Tension AIFree browser tool · Private · No universal thresholds
The short answer
What does a racquet string tension checker tell you?
It compares a current reading with the same racquet's fresh-string baseline. Add your preferred floor to see whether the reading remains inside your own range. The calculation shows change in lbs, kg, and percent; it does not guess a universal restring threshold.
This page interprets a reading; it does not measure your strings. If you need a current measurement, String Tension AI takes a repeatable iPhone reading and saves it to that racquet's history.
Three useful numbers
Build a comparison you can repeat
- 01Fresh baseline
Take a repeatable reading after restringing. This is the comparison point for that racquet—not a universal target.
- 02Current reading
Measure the same racquet again with a consistent environment and routine, then enter the result.
- 03Preferred floor
Set the lowest reading that still belongs to your own playable range, based on tension, feel, control, comfort, and hours.
Read the result
Your range, made visible
A result supports a decision; it is not a diagnosis. Recheck unexpected readings under comparable conditions before changing a setup.
| Status | What it means | Next check |
|---|---|---|
| Inside your range | The reading is at or above your preferred floor and no higher than the fresh baseline. | Keep playing and compare again at your normal interval. |
| Below your floor | The reading is below the lower limit you entered. | Confirm the reading, then weigh tension with feel, comfort, control, wear, and hours before restringing. |
| Above baseline | The current reading is higher than your fresh comparison point. | Repeat the same routine and check whether temperature, environment, racquet setup, or the baseline changed. |
The checker uses only the values you enter. It does not estimate material-specific decay, remaining life, or injury risk.
Checking methods
Choose the right reference
Browser checker
Interprets tension numbers you already have using transparent arithmetic.
Best for: a quick comparisonString Tension AI on iPhone
Takes repeatable readings and tracks the same racquet over time.
Best for: building a trendA stringer's reference setting and a later installed-stringbed reading are not interchangeable. Use each for its intended role and compare repeated readings made with the same method. The tension app accuracy guide explains the quantities and evidence in depth.
Common questions
Racquet tension checker FAQ
Can this web page measure my racquet?
No. This browser checker compares values you enter. To take a current reading on iPhone and keep a history, use String Tension AI.
What should I use as a fresh baseline?
Use a repeatable reading taken soon after restringing. Keep the racquet, environment, and measurement routine consistent when you compare later readings.
How much tension loss is too much?
There is no universal percentage for every player and setup. Use your preferred floor together with control, comfort, playing hours, and repeated measurements.
Are lbs and kg both supported?
Yes. The checker accepts either unit and always reports the change in lbs, kg, and percent. One pound equals exactly 0.45359237 kilograms.
Is reference tension the same as current stringbed tension?
Not necessarily. Reference tension is the stringer's machine setting. Installed stringbed behavior changes after stringing and over time, so compare repeated readings made with a consistent method.
Does higher string tension mean more control?
As a general starting principle, higher tension tends to favor control while lower tension tends to favor power and comfort. Stay inside the racquet manufacturer's range and adjust for string construction and personal needs.
Sources and method
Transparent math, primary references
Change = current reading − fresh baseline. Percent change = change ÷ fresh baseline × 100. Headroom = current reading − preferred floor. The tool converts units using the exact international conversion of 1 lb = 0.45359237 kg.
The interpretation deliberately uses your floor instead of a population-average replacement threshold. String choice, frame, gauge, environment, playing history, comfort, and preference all affect the decision.
Reviewed August 9, 2026
- Wilson — What String Tension Should I Use in My Tennis Racket? for construction ranges and the higher-tension control / lower-tension power starting principle.
- Babolat — How to Choose Your Tennis String for the role of string construction, gauge, tension, and player objective.
- International Tennis Federation — Rackets and Strings: Strings for stringbed fundamentals and tension change over time.
Turn the next reading into a trend
Measure, save, and compare your racquet over time. Core measurements are free.
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