Build a first-pass satellite downlink budget from transmitter power, antenna gains, path loss, receiver losses, and receiver sensitivity. The calculator reports received power and link margin, making it easy to see whether an RF power allocation leaves enough room for pointing, weather, and implementation uncertainty.
Transmit power (dBm) = 10 log10(power in watts × 1,000). Received power = transmit dBm + transmit gain + receive gain − path loss − other losses. Link margin = received power − receiver sensitivity.
Treat the main result as an engineering estimate based on the stated inputs. Compare it with the applicable mission requirement and retain enough traceability to update the result when assumptions change.
This calculator supports early trade studies and does not replace mission-specific simulation, environmental analysis, or professional engineering review.
A 10 W transmitter is 40 dBm. With 6 dBi transmit gain, 35 dBi receive gain, 190 dB path loss, and 4 dB other loss, received power is −113 dBm and margin over −135 dBm sensitivity is 22 dB.
It uses the values shown in the input panel and the formula stated on this page. It does not add hidden operational or environmental allowances.
Yes. Decimal values are accepted within each field’s displayed range, and calculations retain precision until the result is formatted.
Use a value justified by your project’s maturity, uncertainty policy, and verification plan rather than treating the default as a universal recommendation.
No. It is a first-pass estimate for trade studies. Verify the design with subsystem models, test data, and mission-specific constraints.
Zero is accepted where it represents a physically meaningful absence of load, loss, background, duty, or maneuver demand. Inputs used as divisors must remain above zero.
| Item | Use |
|---|---|
| Primary inputs | Enter values in the units printed beside each field. |
| Margin or reserve | Applied only where stated in the formula. |
| Displayed result | Rounded for readability; internal math keeps full precision. |