Flow Meter K Factor Calculator

Work out flow meter k factor instantly with clear inputs, formula shown and shareable results.

About Flow Meter K Factor Calculator

K factor is the number of pulses a flow meter produces per unit volume, so volume is pulse count divided by K. Flow rate follows from volume over time. K factor is not perfectly constant: it varies with viscosity and flow rate, which is why meters are calibrated over their working range.

Formula

K factor

volume = pulses / K; flow rate = volume / time

Worked example

With the default values below, Flow Meter K Factor Calculator returns Volume measured of 15.33. Change any input above and every figure here is recalculated in your browser.

Inputs used

Pulses counted: 18,400 pulses
K factor: 1,200 pulses/L
Measurement duration: 90 s

Results

Volume measured: 15.33 L
Average flow rate: 10.22 L/min
Pulse frequency: 204.44 Hz
Volume per pulse: 0.83333 mL

Step by step

1Values used
2K factor
3Volume measured= 15.33 L
4Average flow rate= 10.22 L/min
5Pulse frequency= 204.44 Hz
6Volume per pulse= 0.83333 mL

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 5 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why does K factor drift with flow rate?

At low flow, bearing drag and viscous effects slow the rotor relative to the fluid, so the meter under-reads. Manufacturers publish a linearity curve.

How do I improve resolution?

Choose a meter with a higher K factor, or count over a longer interval. Resolution is one pulse, so a 1,200 pulses/L meter resolves 0.83 mL.