Package Pin Count Calculator

Work out package pin count instantly with clear inputs, formula shown and shareable results.

About Package Pin Count Calculator

Pin count is signals plus power and ground, and the power ratio is substantial — typically 0.3 to 0.6 power/ground pins per signal — because current delivery and return-path integrity demand it. The resulting square grid at the chosen pitch sets the minimum package body size.

Formula

Pin count

total = (signals x (1 + power ratio)) x (1 + spare); grid side = ceil(sqrt(total)) x pitch

Worked example

With the default values below, Package Pin Count Calculator returns Total pins required of 975. Change any input above and every figure here is recalculated in your browser.

Inputs used

Signal pins: 640 pins
Power and ground ratio: 0.45 x
Spare pins: 5 %
Ball pitch: 0.8 mm

Results

Total pins required: 975 pins
Power and ground pins: 288 pins
Ball array side length: 25.60 mm
Grid dimension: 32 balls

Step by step

1Values used
2Pin count
3Total pins required= 975 pins
4Power and ground pins= 288 pins
5Ball array side length= 25.60 mm
6Grid dimension= 32 balls

Assumptions and limits

The result is derived only from the 4 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 2 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 so many power and ground pins?

Each carries limited current and each signal needs a nearby return path. High-speed IO can need one ground per two signals to control inductance.

What limits ball pitch?

PCB routing: escaping traces between balls needs space. Below 0.65 mm pitch the board usually needs microvias and more layers.