Flow Rate Calculator
Calibrate your extrusion multiplier with a simple measurement.
Print a 100mm calibration cube and measure the actual dimension to calculate the correct flow rate multiplier.
Flow rate, also called the extrusion multiplier, controls how much filament your printer pushes through the nozzle relative to the slicer's expected amount. If the multiplier is too low, you will see gaps between perimeters, weak layer adhesion, and rough top surfaces. If it is too high, parts become over-packed, leading to bulging walls, elephant's foot on the first layer, and inaccurate dimensions.
To calibrate, print a single-wall test cube and measure the wall thickness with digital calipers. Enter the expected wall width (usually equal to your nozzle diameter) and the measured value into this calculator. It returns the corrected multiplier so your slicer extrudes just the right amount of plastic. Most printers need a multiplier between 0.90 and 1.05 depending on filament brand and nozzle wear.
Recalibrate whenever you switch filament brands, replace a nozzle, or notice dimensional accuracy issues. Accurate flow is the foundation for good prints — once dialed in, settings like retraction and print speed become much easier to fine-tune.