Sewing projector calibration calculator
Correct projector scale from a projected test square and reveal horizontal-versus-vertical distortion.
Your measurements
01 / INPUTUse the units shown beside each field. Whole counts must be whole numbers.
Your result
02 / PLANNo saved baseline.
What changes when…
Baseline comparison
Save a baseline, then change your inputs. The difference is current minus baseline. Saved values stay in this browser.
| Result | Baseline | Current | Difference |
|---|
Use the result
Square the projection to the work surface first. Apply a scale correction only after both axes measure consistently.
Assumptions that matter
- Measure a test square on the cutting surface, not the wall or projector housing.
- Different horizontal and vertical corrections suggest tilt, keystone or aspect-ratio distortion. One uniform zoom cannot fix both.
- Disable fit-to-page scaling and check several positions across the projection.
- Recheck calibration after moving the table, projector or cutting mat.
Common questions
How is the result calculated?
The formula reference shows every equation and defines the input variables. Whole-item results explicitly round to whole quantities where needed.
How should I use the example?
The initial numbers are a worked example. Replace them with measurements from your own project before making a plan. Three calculated scenarios appear on the examples page.
Can I compare two plans?
Yes. Save a baseline, change one or more inputs, and compare the result table. The chart changes only one input at a time.
Does this upload my measurements?
No. Calculations run in this browser. Saving a baseline uses local browser storage; the scenario-link button includes entered numbers in a URL fragment you choose to share.
Need a paper record? Use the measurement worksheet.