dB Calculator (dBm ↔ mW, Frequency ↔ Wavelength)

A tiny, client-side RF utility that runs in any modern browser. It converts:

• dBm → mW
• mW → dBm
• Frequency ↔ Wavelength (in free space)
• A simple mW → dB relative to 1 W helper (see notes)

This is the HTML tool you placed at /db-calc.html and also embedded on your portfolio homepage.

---

🎯 Features

• Zero dependencies (plain HTML + JavaScript)
• Instant results, no backend
• Works offline
• Minimal UI that fits a portfolio site

---

🧮 Conversions & Formulas

dBm → mW

• Formula: ( P_{\text{mW}} = 10^{\frac{P_{\text{dBm}}}{10}} )
• Example: 0 dBm → 1 mW; 30 dBm → 1000 mW

mW → dBm

• Formula: ( P_{\text{dBm}} = 10 \log_{10}(P_{\text{mW}}) )
• Example: 1 mW → 0 dBm; 0.1 mW → −10 dBm

Frequency → Wavelength (free space)

• Formula: ( \lambda = \frac{c}{f} )
• Where: ( c = 299{,}792{,}458 ) m/s
• Units: ( f ) in Hz, ( \lambda ) in meters
• Example: 1 GHz → 0.299792458 m

Wavelength → Frequency (free space)

• Formula: ( f = \frac{c}{\lambda} )
• Units: ( \lambda ) in meters, ( f ) in Hz
• Example: 0.5 m → 599,584,916 Hz (~0.6 GHz)

“Convert to dB” helper (relative to 1 W)

• Current formula in the tool: 10 * log10(1000 / mW)
  This equals ( 30 - 10\log_{10}(P_{\text{mW}}) ) which is −dBW (dB relative to 1 W).
  • If you actually want dBW, use ( \text{dBW} = 10\log_{10}(P_{\text{W}}) = 10\log_{10}(P_{\text{mW}}) - 30 ).
  • The current helper is useful when you want the attenuation to 1 W as a positive dB number.

✅ If you’d like, I can switch this helper to output dBW directly and label it accordingly.

---

📦 File

• db-calc.html — Standalone page containing the UI and JS.

---

🚀 Run locally

Just open the file in a browser:

# macOS
open db-calc.html

# Windows
start db-calc.html

# Linux (GNOME)
xdg-open db-calc.html