Radiation Exposure: WiFi Calling vs. Cellular Calls
In this post I will try to address the issue of radiation exposure in the context of WiFi Calling vs Regular cellular calls.
Understanding SAR and Phone Radiation
Specific Absorption Rate (SAR) measures the rate at which the body absorbs radiofrequency (RF) energy from a device. It’s expressed in watts per kilogram (W/kg) and is used to ensure phones stay within safety limits. For example, regulators like the FCC in the U.S. cap head SAR at 1.6 W/kg (averaged over 1g of tissue), while Europe uses 2 W/kg (10g average). Most modern smartphones have peak SAR values near these limits during cellular calls at maximum power output. However, these SAR ratings reflect a worst-case scenario (poor signal, maximum transmit power). In everyday use with a strong signal, the phone transmits at a fraction of that power. A German radiation protection agency notes that phones with SAR below ~0.5 W/kg (at the ear) are considered “low radiation,” and about 40% of current smartphones meet this criterion (BFS.DE). Overall, SAR provides a standardized way to compare devices’ radiation, but actual exposure varies with network conditions and usage.