# Round-hoop fit planner

> Find the minimum inner diameter that contains a rectangular design and clearance.

- [Open tool](https://threadcabin.com/tools/round-hoop-fit-planner)
- The page shows its formula, example, assumptions, rounding, and limitations beside the calculator.

## Formula and assumptions

The mathematical minimum inner diameter is the diagonal of the design rectangle after clearance is added on every side. The practical suggestion rounds up to a common 3, 4, 5, 6, 7, 8, 10, or 12 inch hoop; verify the actual inner opening and choose a frame when that diameter is impractical.

## Worked example

Example: an 8 × 6 cm design with 1 cm clearance needs at least a 12.81 cm inner diameter.

## Limits and rounding

Results are planning estimates from the values entered. Displayed decimals are rounded for craft use; whole materials and repeats round up where the method says so. Confirm gauge, material behavior, construction, and finished measurements before committing supplies.