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NETWORK PHYSICS CALCULATOR

Free-Space Path Loss Calculator for Wi-Fi and RF

Free-space path loss increases with both distance and frequency. The calculator models unobstructed line-of-sight spreading only, so walls, reflections, antenna gain and interference must be evaluated separately.

INTERACTIVE MODEL

Calculate the physical limit

Ideal free-space path loss60 dB

Distance10 m

Frequency2,400 MHz

Walls and interferenceNot included

This is an educational lower-bound model, not an address-level performance prediction.

The model

FSPL in dB is 32.44 + 20 log10(distance in km) + 20 log10(frequency in MHz).

Indoor limitation

Indoor Wi-Fi rarely behaves like empty free space. Multipath can help or hurt, while walls and floors introduce additional material-dependent loss.

QUESTIONS

Common questions

Is path loss the same as received signal strength?

No. Received power also depends on transmitter power, antenna gains, cable loss and other losses.

Can this predict Wi-Fi range?

It provides one part of a link budget, not a complete range prediction.

Continue exploring network physics

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Formula and limitations

FSPL(dB) = 32.44 + 20 log10(distance km) + 20 log10(frequency MHz).

Reference constants: NIST speed of light in vacuum. Fiber propagation uses a disclosed engineering approximation of 204,000 km/s; actual group velocity varies with the fiber.