How do I interpret dBm?
Treat P₁ as 1 mW. The converter shows the ratio so you can derive absolute dBm by comparing P₂ to a 1 mW reference.
Step-by-step walkthrough
dB Converter Guide
Use this companion guide beside the interactive calculator to make sure you understand the “why” behind every click. Each section includes the classroom explanation, student-friendly language, and quick practice prompts.
Before you start
Collect the data points listed below and double-check their units. Keeping an organized “givens” list is one of the fastest ways to reduce math errors and impress exam graders.
- decibels
- gain
- dbm
Detailed procedure
Step 1
Choose whether you’re converting a ratio to dB or a dB figure back to a ratio.
Step 2
Select power or voltage/current mode.
Step 3
Enter the known value and copy the converted result.
Teaching & troubleshooting tips
Can ratios be less than one?
Yes—ratios below one simply yield a negative decibel value to represent attenuation.