Shannon Channel Capacity Calculator
What is the theoretical maximum data rate of a channel?
Your numbers
Your results
Capacity (Mbps)
Capacity (Mbps)
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SNR as a plain ratio
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Spectral efficiency (bits/s/Hz)
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Shannon Channel Capacity Calculator by TheCalcTools
How the Shannon Channel Capacity Calculator works
Enter the channel bandwidth and the signal-to-noise ratio in decibels.
The SNR is converted to a plain ratio.
Shannon’s formula gives the maximum error-free rate.
The formula
C = B × log₂(1 + S ÷ N)S ÷ N = 10^(SNR dB ÷ 10)
Worked example
Using the default values shown in the calculator:
| Bandwidth (MHz) | 20 |
|---|---|
| Signal-to-noise ratio (dB) | 30 |
- SNR = 10^(30 ÷ 10) = 1,000.
- Spectral efficiency = log₂(1,001) = 9.967 bits/s/Hz.
- Capacity = 20 MHz × 9.967 = 199.34 Mbps.
Result:
| Capacity (Mbps) | 199.34 |
|---|---|
| SNR as a plain ratio | 1,000.00 |
| Spectral efficiency (bits/s/Hz) | 9.967 |
Frequently asked questions
Is this the speed I will get?
No. It is an upper limit that no coding scheme can exceed. Real systems reach a fraction of it after overhead.
How do I increase capacity?
Add bandwidth or improve SNR. Capacity grows linearly with bandwidth but only logarithmically with signal power.
Sources and further reading
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.