Noise Exposure Calculator
How to Use the Noise Exposure Calculator
Here’s how to use the Noise Exposure Calculator shown in your image:
🔧 Step-by-Step Guide
1️⃣ Noise Level (dB)
Enter the sound level you’re exposed to in decibels (dB).
🟢 Example: 95
OSHA considers 90 dB over 8 hours as the baseline. For every 5 dB increase, the allowable time is halved.
2️⃣ Exposure Duration (in hours)
Enter how long (in hours) you are exposed to that noise level.
🟡 Example: 3.5 (for 3 hours 30 minutes)
3️⃣ Click “Calculate Dose & TWA”
Tap or click the blue button. It will instantly calculate:
- ✅ Noise Dose (%): OSHA considers 100% dose as the maximum legal exposure.
- 📉 TWA (Time-Weighted Average): Equivalent 8-hour exposure in dB.
📊 Behind the Calculator (Formulas)
✅ Noise Dose Formula
- T = Permissible hours at that dB (based on OSHA table)
✅ TWA Formula (OSHA):
💡 Example:
If you enter:
- Noise Level =
95 dB - Exposure =
3.5 hours
The calculator might return:
- Dose =
175%(which is over OSHA limit) - TWA =
93.5 dB
🔊 Noise Exposure Calculator (LEQ / TWA / Dose %)
This tool calculates:
- Equivalent Continuous Noise Level (Leq)
- Time-Weighted Average (TWA)
- Noise Dose (%)
Based on OSHA/NIOSH standards.
🧮 Formula Behind the Tool
✅ TWA (Time Weighted Average dB):
Where:
- D = Dose % (percentage of allowable exposure)
✅ Noise Dose (%) Calculation:
Where:
- Cn = actual exposure duration (in hours)
- Tn = maximum allowed duration at that dB level
🎯 OSHA Permissible Exposure Time Table
| Sound Level (dB) | Max Exposure Time (OSHA) |
|---|---|
| 90 dB | 8 hours |
| 95 dB | 4 hours |
| 100 dB | 2 hours |
| 105 dB | 1 hour |
| 110 dB | 30 minutes |
| 115 dB | 15 minutes |
🧠 Action Levels for Noise Control (OSHA)
| TWA (dB) | Action |
|---|---|
| ≤ 85 | Safe (no action) ✅ |
| 85–89 | Hearing protection required, monitoring needed ⚠️ |
| ≥ 90 | Hearing Conservation Program required 🚨 |