Last checked: August 2026 · Written by the Badminton House player-led team.
Quick answer: badminton string tension kg to lbs
Divide kilogram-force by 0.45359237 to get pound-force. Multiply pound-force by 0.45359237 to get kilogram-force. These exact unit relationships apply to the stringing machine’s reference pull; they do not convert completed-bed DT, N/mm or Hz readings.
kg to lb
kgf ÷ 0.45359237 = lbf. Example: 11.5 kgf ≈ 25.353160 lbf, usually shown as 25.4 lbf.
lb to kg
lbf × 0.45359237 = kgf. Example: 26 lbf = 11.79340162 kgf.
Finished bed
Keep its own unit. DT, N/mm and Hz describe other completed-bed measurements, not reference pounds.
In everyday stringing language, a shop may say “12 kg.” Formally, the kilogram is the SI unit of mass; the intended tension unit is kilogram-force, written kgf. Kilopond, written kp, is numerically the same force. The NIST conversion table gives both kgf and kp as 9.80665 newtons, and NIST footnote 23 gives 1 pound-force as exactly 4.4482216152605 newtons under standard gravity.
Those definitions give 1 lbf = 0.45359237 kgf exactly and 1 kgf = 100000000/45359237 lbf exactly. The latter is approximately 2.204622621848775807 lbf because its decimal expansion does not terminate. What this exact unit relationship does not make exact is the link between a machine setting and the condition of the completed stringbed.
What is the kg-to-lbs conversion table?
Use the table for reference settings only. The pound values are rounded to one decimal place; use the formula when you need more digits. The span is a convenient lookup range, not a recommendation and not permission to exceed the limit stated for your exact racket.
| kgf or kp | lbf | Common spoken form |
|---|---|---|
| 8.0 | 17.6 | “8 kg” |
| 8.5 | 18.7 | “8.5 kg” |
| 9.0 | 19.8 | “9 kg” |
| 9.5 | 20.9 | “9.5 kg” |
| 10.0 | 22.0 | “10 kg” |
| 10.5 | 23.1 | “10.5 kg” |
| 11.0 | 24.3 | “11 kg” |
| 11.5 | 25.4 | “11.5 kg” |
| 12.0 | 26.5 | “12 kg” |
| 12.5 | 27.6 | “12.5 kg” |
| 13.0 | 28.7 | “13 kg” |
| 13.5 | 29.8 | “13.5 kg” |
| 14.0 | 30.9 | “14 kg” |
| 14.5 | 32.0 | “14.5 kg” |
| 15.0 | 33.1 | “15 kg” |
A current Yonex badminton-capable stringing machine publishes its setting range in both pounds and kilograms. The page’s dual-unit display is one concrete manufacturer example; when precision matters, write kgf and lbf in your notes so the force quantity is unambiguous.
Is the machine setting the finished stringbed tension?
No. The requested kgf or lbf value is a reference pull: the tensioner applies that force to a string segment during the job before the stringer clamps it. After weaving, clamping, tying off and removing the racket from its supports, the completed bed has a distribution of residual string forces and an overall stiffness. Those are related to the reference pull, but they are not the same quantity.
| Number | What it describes | How to record it |
|---|---|---|
| Reference pull | Force set on the tensioning machine for a pull. | kgf or lbf, including separate mains and crosses if used. |
| Residual string force | Force remaining in an individual string or an estimated average after completion. | Name the device or method, unit and measurement time. |
| Stringbed stiffness or DT | Force needed to deflect the completed bed by a stated distance. | DT, kp/cm or N/mm, with the instrument named. |
| Frequency | How quickly the completed bed vibrates under a defined test. | Hz, plus the app or instrument, string and racket. |
The distinction is measurable. A peer-reviewed tennis-racket study found that average completed-string tension differed substantially from pull tension because of stress relaxation, frame distortion and friction. Its exact percentages are tennis-specific and are not a badminton correction. Do not subtract a fixed percentage from your badminton request.
A finished-bed meter may also report an entirely different unit. ERT Technic’s tennis stringbed FAQ defines dynamic tension in kp/cm or N/mm and lists the reference setting as only one influence. A DT value therefore does not mean the same number of pounds or kilogram-force. It is a stiffness result from that measurement system.
Why can two jobs at the same number differ?
The unit may be identical while the process is not. ERT Technic’s tennis FAQ lists the reference setting, machine accuracy and condition, stringer technique, string material and diameter, head size and pattern as influences on its DT result; the Cross and Bower tennis-racket study separately identifies stress relaxation, frame distortion and friction in tension loss during stringing. Neither source establishes a universal badminton kg-to-lb offset. The force-unit arithmetic remains exact; meaningful comparisons need the complete recorded recipe.
For the full process explanation, read why the same badminton tension can feel different. If a number came from an elite setup, use the pro string-tension guide before treating it as a target. This article converts units; it does not decide which reference tension suits a player or frame.
How should you communicate tension to a stringer?
Give the reference force and the repeatability details together. One number is enough for conversion, but not enough to reproduce a completed bed across different strings, rackets and processes.
- Normalize the unit. Write the original request first, then the conversion: “11.5 kgf ≈ 25.353160 lbf reference (rounded).” Do not silently round it to 25 or 26 lb.
- Name the complete reference setting. Record mains and crosses separately when they differ, and confirm that every value is a machine setting rather than a finished-bed reading.
- Keep the material identifiable. Record the exact string and gauge. A different construction makes a different comparison even when the machine setting is unchanged.
- Record the process. Note the stringer, machine or tensioner type, and whether pre-stretch was used. Do not apply an invented correction between machines.
- Label any finished measurement. Write the device, result, unit and elapsed time after stringing. “DT ___ after ___ hours” and “___ Hz after ___ hours” are useful records; neither result is a reference pull in pounds.
- Change one variable next time. If you want a different result, keep the rest of the recorded recipe stable so the comparison has meaning.
Copyable job note: Racket: ___ · String and gauge: ___ · Mains reference: ___ kgf / ___ lbf · Crosses reference: ___ kgf / ___ lbf · Machine or tensioner: ___ · Pre-stretch: ___ · Completed-bed reading, method and time: ___ · First-session note: ___
Use the kgf ÷ 0.45359237 relationship only when both numbers are forces: kgf and lbf. If you multiply instead, 2.204622621848776 is a rounded convenience factor. Once the racket is off the machine, keep every finished-bed result in its own named unit and compare it through a repeatable record.
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