Calculate recurve or longbow string length from the marked bow length (about 3 in shorter), or work back from a string to the bow length it fits.
Nominal Bow String Starting-Length Method
This calculator estimates physical string length from a chosen deduction. Manufacturer guidance commonly describes approximately 3 inches less than marked bow length, but material, measurement tension and the exact bow control. An AMO ordering size may already name the bow length; do not subtract again when a supplier requests that size.
How the Calculation Works
Subtract the selected deduction for physical string length, or add it for estimated marked bow length. Custom deduction uses the exact value supplied by the maker.
How to Use This Calculator
- Select the value or workflow you want in the Solve for menu.
- Enter only the visible source values and use the units shown beside them.
- Select Calculate and review the primary answer, supporting values, warning, and steps.
- Use Reset before starting a different bow, arrow, or round.
Worked Example
For a 68-inch recurve and the approximate 3-inch reference deduction, the estimated physical string length is 65.00 inches. This does not change an AMO order size of 68 inches when the supplier orders by bow length.
Input and Result Guide
| Item | How to use it |
|---|---|
| Recurve | The calculator uses an approximate 3-inch reference deduction; verify the maker’s measurement method. |
| Longbow | The calculator uses an approximate 3-inch reference deduction; verify the exact bow and string specification. |
| Custom | Enter the exact deduction supplied by the bow or string maker. |
| Finished string | Confirm under the maker’s tension and measurement convention. |
| Brace height | Tune only within the safe range for the actual bow and string material. |
Interpreting the Result
The result is a purchasing or build starting point. Small differences in construction, strand count, material, serving, and measurement tension affect the finished string.
Assumptions and Limitations
The nominal deductions are not universal manufacturing dimensions and do not apply to compound cables or strings. The bow maker’s specification and achieved brace height control.
Common Questions
Why did a field disappear after I changed Solve for?
A hidden field is either the requested output or irrelevant to the selected workflow. Enter the remaining visible source values.
Will my last successful calculation be restored?
Yes, when browser storage is available. It restores values and recomputes the result; edits mark it stale. Reset clears saved state.
Sources
60X Custom Strings, “Measuring String: How to Properly Measure a Bow String”; Hoyt Recurve Owner’s Manual. Measurement and ordering conventions matter; follow the exact maker’s instructions.