Here, you can convert decibel milliwatts (dBm) to milliwatts (mW) and vice versa. – dBm and mW are two crucial units used in fibre optics, wireless communications and signal analysis. We also converted the mW value to W, kW, and MW for your convenience. **Understanding this conversion is paramount for accurately measuring and interpreting power levels in various applications.**

## The Fundamental Formula

dBm (decibel-milliwatts) is a unit that expresses relative power levels in electrical systems. It provides a more compact representation of power than absolute units like milliwatts (mW) or watts (W). Here’s the key concept:

- dBm is a
**logarithmic unit**, meaning that equal increases in dBm don’t correspond to equal increases in actual power. A small change in dBm can represent a significant change in absolute power.

**The Reference Point: 1 mW = 0 dBm**

dBm is based on a reference power level of **1 milliwatt (mW)**. This value is assigned 0 dBm. Any power level above or below 1 mW is expressed as a positive or negative dBm value.

**Conversion Formulas:**

At the core of this calculation lies the **formula for converting dBm to mW**

**Convert mW to dBm:**

\(P(dBm)=10\ \log_{10}(\frac{P(mW)}{1mW})\)

**Convert dBm to mW:**

\(P(mW)=1mW\ \ 10^{P(dBm)/10)}\)

Explanation:

- dBm is a unit of power referenced to 1 milliwatt (mW).
- The formula uses the concept of exponents to represent the relative power level in dBm.
- 10^(P(dBm)/10) calculates the multiplier based on the dBm value.
- 1 mW serves as the reference power level (0 dBm).

## Rules of Thumb

While the formula provides precision, sometimes you may need quick estimates. Here are some handy **rules of thumb**:

**0 dBm = 1 mW****+3 dB increase doubles the power in mW****-3 dB decrease halves the power in mW****+10 dBm multiplies mW by 10****-10 dBm divides mW by 10**

Also, here is the dBm to mW conversion table for more reference