Browser-only OrcaSlicer calibration tool

Pressure Advance Tower Calculator

Read the pressure advance value off a printed PA test. Enter the start value and the increment the tower was sliced with, plus the step or layer that printed cleanest, and get the exact number to type into the filament profile — along with the values the neighbouring steps printed at and a narrower re-test to confirm it. Every calculation runs in this page.

1 — Set up the test

Copy these three numbers from the pressure advance test you sliced in OrcaSlicer. They describe the ramp the tower printed, not the print result.

The value the first step of the test printed at — the start value in the calibration dialog. Use 0 if the tower started at zero.

How much the pressure advance value rises with each step or layer band. Common choices are 0.002 or 0.005.

How many steps the tower or pattern has. Used to check your reading and to show the range the test covered.

2 — Read the tower

Look at the printed test and find the step or layer band with the cleanest corners: the sharpest detail with no bulging and no gaps.

Towers are usually labelled by step; a pattern or line test is easier to read as a layer number.

The 1-based step number, counted from the bottom of the tower.

Result

Enter the start value, the increment and the number of steps, then the step or layer that printed cleanest, and selectCalculate pressure advance.

How the pressure advance value is calculated

A pressure advance tower prints the same geometry over and over, each step at a constant pressure advance value, and the value rises by a fixed increment from the bottom to the top. Reading the cleanest step is therefore a matter of counting steps and multiplying:

pressure advance = start value + (step − 1) × increment

Worked example: a test sliced from 0.0000 in steps of0.0020, where step 7 has the cleanest corners:0.0000 + (7 − 1) × 0.0020 = 0.0120. That is the value to save — the steps around it printed at 0.0100 and 0.0140, so the clean window is narrow and worth confirming with a finer test.

When you read the print as a layer number instead, the calculator first converts the layer to a step: it subtracts the layer the first step starts on, divides by the layers per step, and rounds down. A clean band that spans several layers maps to the step that covers them.

Reading the tower accurately

  1. Print the test with the filament and nozzle you want to calibrate, at the speeds and temperatures you actually print with.
  2. Let it cool, then look at the corners and the seam side rather than the flat walls — pressure advance shows up as bulging or gaps where the direction changes.
  3. Find the band with the sharpest corners: no rounded bulge at the corner and no gap or pinhole after it.
  4. Note the step or layer number of that band and enter it here with the start value and increment you sliced with.
  5. Save the value into the filament profile, then reprint the test to confirm before using it on a real model.

What the reading does and does not tell you

  • It converts an observation into one number. The arithmetic is exact for your inputs, but it can only be as good as the step you picked off the print.
  • It is per filament, nozzle and extruder. Pressure advance compensates for the compression in your own hotend, so the value has to be calibrated on the machine and the spool you print with.
  • It is not a diagnosis. A tower that never looks clean usually points at a mechanical problem — a loose belt, a worn nozzle, a slipping extruder or wet filament. Fix that first; the calculator cannot see it.
  • The increment sets the resolution. With steps of 0.002 the value is only meaningful to about that precision; that is why the page offers a narrower re-test around the best step.
  • Values are unitless. OrcaSlicer stores pressure advance as a plain number in the filament profile and translates it for the firmware, so enter the number exactly as it appears on the test.

Frequently asked questions

Where does the pressure advance value go in OrcaSlicer?

Filament settings → Filament → Pressure advance. It is stored in the filament profile, so it travels with the spool to every printer you slice that profile for.

Which pressure advance test does this work with?

Any test that ramps the value in fixed steps: the tower, the line and the pattern variants of the built-in calibration, and a manual test you sliced yourself. You only need the start value, the increment and the step or layer that printed cleanest.

My tower has no step labels — what do I enter?

Switch the reading mode to layer number and enter the layer the clean band sits on, plus the layers per step the calibration dialog used. The calculator divides the layers by that number to work out the step.

Should I use the value exactly as calculated?

Yes as a starting point, then confirm it. Reprint the test with the new value, or run the narrower re-test the calculator suggests, and keep the value that actually prints cleanest rather than the one that looks best on paper.

Does the calculator send my numbers anywhere?

No. The arithmetic runs in this page, and nothing you type is uploaded, logged or transmitted.

Save the value where it belongs

A pressure advance reading only pays off once it lives in the filament profile and gets reused on every spool of that material.

How to save and reuse filament profilesFlow ratio calculator