Printsize Lab.
Practical printing tools

Print calibration calculator: correct your print scale

Enter the intended length, measured horizontal and vertical lengths, and current print percentage to calculate a next test setting.

Measurement-based correction

Enter both measurements, then calculate. Use equal intended-length marks on both axes.

Use a known numeric print percentage. If the previous print used an unknown automatic Fit setting, make a fresh test at 100% first.

Equal 96 mm readings on both axes of a 100 mm test give a 104.17 percent correction from a 100 percent setting.
Equal 96 mm readings on both axes of a 100 mm test give a 104.17 percent correction from a 100 percent setting.

Print, measure, calculate, repeat

  1. Download the A4 or Letter test sheet matching your paper.
  2. Select one page per sheet and Actual Size / 100%. Check the paper size in the application and printer settings.
  3. Measure both 100 mm marks with a physical ruler, using the stated endpoints.
  4. Enter the readings above. Apply the calculated correction only if a uniform resize makes sense.
  5. Print one new test and remeasure. Check the page edges for clipping.

Worked example: 100 mm prints as 96 mm

Next percentage = current percentage × intended length ÷ measured length

At a current setting of 100%, both axes measuring 96 mm give 100 × 100 ÷ 96 = 104.17%. If the same measured output was produced at 95%, the next setting would instead be 98.96%. Record the original setting; the measurement alone is not enough.

When the two axes disagree

If the horizontal mark measures 96 mm and the vertical mark measures 99 mm, their corrections are 104.17% and 101.01%. One uniform percentage cannot make both exact. Remeasure, check the original document and inspect the application’s scaling options. Small differences can also come from ruler placement or measurement precision.

This helper models proportional scaling, not a hardware calibration procedure. Large or uneven errors need investigation. It does not fix duplex registration, feed skew or a blurred image. Read the correction guide or choose a symptom in printing troubleshooting.