The conversion of 28 dBm to watts results in approximately 0.631 watts.
This calculation is based on the formula that relates decibel-milliwatts (dBm) to watts, where each increase in 10 dB multiplies the power by ten. Converting 28 dBm involves exponentiating 10 to the power of (28 minus 30) divided by 10, resulting in the watts equivalent.
Conversion Calculation
To convert 28 dBm to watts, use the formula: P(watts) = 10^((dBm – 30) / 10). This works because dBm is a logarithmic measurement of power relative to 1 milliwatt. Substituting 28 for dBm gives: P = 10^((28 – 30) / 10) = 10^(-2 / 10) = 10^-0.2 ≈ 0.631 watts.
Conversion Tool
Result in watts:
Conversion Formula
The formula used to convert dBm to watts is P(watts) = 10^((dBm – 30)/10). The reason is that dBm is a logarithmic scale, and to find the actual power in watts, you exponentiate 10 to the power of the dBm value minus 30, divided by 10. This is because 0 dBm equals 1 milliwatt, and each 10 dB increase represents a tenfold increase in power. For example, converting 28 dBm:
- Subtract 30 from 28: 28 – 30 = -2
- Divide by 10: -2 / 10 = -0.2
- Calculate 10^(-0.2): approximately 0.631 watts
Conversion Example
- Convert 20 dBm to watts:
- Subtract 30: 20 – 30 = -10
- Divide by 10: -10 / 10 = -1
- Calculate 10^(-1): 0.1 watts
- Convert 35 dBm to watts:
- Subtract 30: 35 – 30 = 5
- Divide by 10: 5 / 10 = 0.5
- Calculate 10^(0.5): approximately 3.162 watts
- Convert 15 dBm to watts:
- Subtract 30: 15 – 30 = -15
- Divide by 10: -15 / 10 = -1.5
- Calculate 10^(-1.5): approximately 0.0316 watts
Conversion Chart
| dBm | Watts |
|---|---|
| 3.0 | 0.001995 |
| 8.0 | 0.00631 |
| 13.0 | 0.01995 |
| 18.0 | 0.0631 |
| 23.0 | 0.1995 |
| 28.0 | 0.631 |
| 33.0 | 2.000 |
| 38.0 | 6.310 |
| 43.0 | 19.95 |
| 48.0 | 63.10 |
| 53.0 | 199.5 |
This chart helps you see the watts equivalent for various dBm values. To use, find your dBm value in the first column and look across to see the corresponding watts, which shows the power level directly.
Related Conversion Questions
- What is the power in watts for 28 dBm signal?
- How do I convert 28 dBm to milliwatts?
- What is 28 decibel-milliwatts in watts?
- Can you tell me the watt equivalent of 28 dBm?
- How much wattage is represented by 28 dBm in wireless systems?
- Is 28 dBm equal to any known watt value?
- How do I go from 28 dBm to watts step-by-step?
Conversion Definitions
dbm
Decibel-milliwatts (dBm) is a logarithmic unit measuring power relative to 1 milliwatt, used mainly in radio, telecommunications, and audio to express signal strength, where each 10 dB increase signifies ten times more power.
watts
Watts are the SI unit of power, representing the rate of energy transfer or conversion, used across electrical, mechanical, and thermal systems to quantify the amount of work performed or energy used per second.
Conversion FAQs
What does 28 dBm mean in terms of power output?
28 dBm indicates a power level of about 0.631 watts, showing the amount of energy transmitted in a system relative to 1 milliwatt, often used in wireless communication equipment to specify signal strength.
Why is the conversion from dBm to watts logarithmic?
The conversion is logarithmic because dBm measures power on a log scale to handle large variations in signal strength efficiently. It allows expressing very high or low power levels compactly, making calculations manageable across different ranges.
Can I convert dBm to watts manually without a calculator?
Yes, but it involves logarithmic calculations, so using a calculator or conversion table simplifies the process. You subtract 30 from your dBm value, divide by 10, then raise 10 to that power to find the watts equivalent.
Last Updated : 22 July, 2025
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Sandeep Bhandari holds a Bachelor of Engineering in Computers from Thapar University (2006). He has 20 years of experience in the technology field. He has a keen interest in various technical fields, including database systems, computer networks, and programming. You can read more about him on his bio page.