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Correction: This lesson previously displayed age-based penetration percentages and SAR estimates. Those outputs were not validated measurements or predictions for your child and have been removed.
1. Start with the question
“How much energy is absorbed?” and “Does an exposure cause a health effect?” are different questions. A model output cannot answer both. Age and distance alone do not provide enough information to calculate an individual's exposure.
2. What an absorption model needs
A meaningful model specifies the device and antenna, frequency, transmit power, position, tissue properties and anatomy, and how the calculation was validated. Findings apply to those conditions. A result for one model is not a universal multiplier for every child.
SAR describes absorbed power per mass, in W/kg. An ordinary room RF reading is not a measurement of brain SAR. Do not convert it into a cranial penetration percentage.
3. Put health evidence in context
The FDA's cellphone guidance says the available scientific evidence does not establish RF danger to cellphone users, including children and teenagers. That statement is about cellphone RF; it is not a guarantee for every source, exposure situation or medical device.
Research findings should be assessed with their limitations and the wider evidence. Neither a dramatic graphic nor a single study establishes an individual's risk.
4. Practical choices without a risk score
If you want more separation during calls, consider speaker mode or a suitable headset. Follow the device manufacturer's operating instructions. A stand can make a tablet more comfortable to use; this page does not assign it a universal percentage reduction or a medically safe distance.
Keep electrical, charging and screen-use considerations separate from RF measurements. Do not use a room-planning illustration to diagnose symptoms.
Check your understanding
Can a child's age and distance from a phone determine their brain SAR?
Reveal the answer
No. The device, operating conditions and a validated dosimetry method are also required. This lesson intentionally does not calculate a child's exposure or health risk.
Sources and limits
- FDA: cellphones, children and scientific evidence — public-health context.
- ICNIRP 2020 RF guidelines — technical exposure quantities and assessment conditions.
Editorial update: 17 October 2026. Educational explanation; no individual exposure assessment.