The Sones to dB Converter is a free online tool that instantly converts between sones (perceived loudness) and decibels (dB) for accurate sound level measurements.
Whether you’re shopping for bathroom exhaust fans, range hoods, or comparing appliance noise ratings, this converter helps you understand real-world sound levels. Enter your sone value and get instant decibel conversions with helpful noise comparisons.
sones
Perceived loudness
dB
Sound intensity
Conversion Result
40.00
decibels (dB)
1 sone = 40 dB at 1 kHz reference
🤫 Silent (20 dB)
🗣️ Moderate (50 dB)
📢 Loud (80 dB)
Quiet
Similar to a quiet refrigerator or library
Loudness Ratio
1.0×
vs 1 sone
Phons
40
phons
Sound Pressure
0.002
Pa
Intensity
10⁻⁸
W/m²
📝 Conversion Formulas
dB = 40 + 33.22 × log₁₀(sones) | sones = 10^((dB – 40) / 33.22)
📖 How to Use This Converter
1
Enter Sones
Type the sone rating from your appliance specs
2
View dB Result
Get instant decibel conversion
3
Compare Noise
See real-world sound comparisons
4
Make Decision
Choose quieter appliances confidently
⚖️ Understanding Sones and Decibels
🔊 Sones
- MeasuresPerceived Loudness
- Scale TypeLinear
- 2× sones =2× as loud
- Reference1 sone = 40 dB
- Common UseFans, Appliances
- RegionNorth America
📢 Decibels (dB)
- MeasuresSound Intensity
- Scale TypeLogarithmic
- +10 dB =10× intensity
- Reference0 dB = hearing threshold
- Common UseAcoustics, Audio
- RegionWorldwide
🎚️ Noise Level Comparison Guide
Very Quiet
0.3-0.5 sones (25-30 dB)
Whisper, rustling leaves
Quiet
0.5-1.0 sones (30-40 dB)
Library, quiet room
Low
1.0-2.0 sones (40-50 dB)
Refrigerator, light rain
Moderate
2.0-4.0 sones (50-60 dB)
Normal conversation
Noticeable
4.0-6.0 sones (60-66 dB)
TV, office noise
Loud
6.0+ sones (66+ dB)
Vacuum, busy traffic
🏠 Appliance Noise Rating Guide
🚿 Bathroom Exhaust Fans
Premium Quiet
0.3-0.5 sones
Standard Quiet
0.5-1.0 sones
Budget/Economy
2.0-4.0 sones
High CFM Models
3.0-6.0 sones
🍳 Range Hoods
Low/Whisper
1.0-2.0 sones
Medium Speed
3.0-5.0 sones
High Speed
5.0-8.0 sones
Max/Boost
8.0-12.0 sones
❄️ HVAC & Ventilation
Whole House Fans
2.0-5.0 sones
Attic Fans
2.5-4.5 sones
Inline Fans
0.5-2.0 sones
ERV/HRV Units
1.0-3.0 sones
💡 Recommended by Room
Bedroom
< 1.0 sones
Bathroom
< 1.5 sones
Kitchen
< 4.0 sones
Utility/Garage
< 6.0 sones
📊 Quick Conversion Reference
| Sones | Decibels | Loudness | Example |
|---|---|---|---|
| 0.3 | 25 dB | Very Quiet | Whisper |
| 0.5 | 30 dB | Very Quiet | Quiet library |
| 0.8 | 37 dB | Quiet | Quiet room |
| 1.0 | 40 dB | Quiet | Refrigerator |
| 1.5 | 46 dB | Low | Light rain |
| 2.0 | 50 dB | Low | Quiet conversation |
| 3.0 | 56 dB | Moderate | Normal conversation |
| 4.0 | 60 dB | Moderate | Background music |
| 6.0 | 66 dB | Noticeable | Busy office |
| 8.0 | 70 dB | Loud | Vacuum cleaner |
| 10.0 | 73 dB | Loud | Busy traffic |
| Decibels | Sones | Loudness | Example |
|---|---|---|---|
| 25 dB | 0.3 | Very Quiet | Whisper |
| 30 dB | 0.5 | Very Quiet | Quiet library |
| 35 dB | 0.7 | Quiet | Soft music |
| 40 dB | 1.0 | Quiet | Refrigerator |
| 45 dB | 1.4 | Low | Quiet office |
| 50 dB | 2.0 | Low | Moderate rain |
| 55 dB | 2.8 | Moderate | Coffee shop |
| 60 dB | 4.0 | Moderate | Normal TV |
| 65 dB | 5.7 | Noticeable | Loud conversation |
| 70 dB | 8.0 | Loud | Vacuum cleaner |
| 75 dB | 11.3 | Very Loud | Busy street |
🎯 Buying Tip
When comparing fans or appliances, remember that sones provide a more intuitive comparison. A 2-sone fan is literally twice as loud as a 1-sone fan. Look for ratings under 1.0 sone for quiet operation in living spaces.
📐 Why Sones Matter
Decibels can be misleading because they use a logarithmic scale. A 50 dB sound doesn’t “feel” 25% louder than 40 dB. Sones give you a direct comparison – making them ideal for product shopping.
⚠️ Installation Note
Actual noise levels may vary from rated sones due to installation quality, ductwork, and mounting. Proper installation with flexible duct connectors can reduce vibration noise significantly.
❓ Frequently Asked Questions
How do I convert sones to decibels?
Use the formula: dB = 40 + 33.22 × log₁₀(sones). For example, 2 sones = 40 + 33.22 × log₁₀(2) = 40 + 10 = 50 dB. Our calculator does this instantly for any value you enter.
How many decibels is 1 sone?
1 sone equals 40 decibels at the standard reference frequency of 1 kHz. This is roughly equivalent to the sound of a quiet refrigerator running or a very quiet room with minimal background noise.
What is a good sone rating for a bathroom fan?
For quiet operation, look for bathroom fans rated at 1.0 sone or less. Premium quiet fans are rated at 0.3-0.5 sones and are virtually silent. Fans rated above 2.0 sones may be noticeably loud during operation.
What is the difference between sones and decibels?
Sones measure perceived loudness (how loud something sounds to humans), while decibels measure sound intensity (physical sound pressure). Sones use a linear scale where 2 sones is twice as loud as 1 sone, but decibels use a logarithmic scale where +10 dB means 10× more sound energy.
Is 4 sones loud for a range hood?
4 sones (about 60 dB) is moderately loud – comparable to normal conversation or background music. It’s acceptable for range hoods during cooking but may be noticeable. Quieter range hoods operate at 1-2 sones on lower speed settings.
What does 0.5 sones sound like?
0.5 sones (about 30 dB) is very quiet – similar to a quiet library or gentle rustling of leaves. You’ll barely notice a fan operating at this level, making it ideal for bedrooms, home offices, and other quiet spaces.
How do sones relate to each other?
Sones use a linear scale for perceived loudness. This means 2 sones sounds twice as loud as 1 sone, 4 sones sounds four times as loud as 1 sone, and so on. This makes sones intuitive for comparing product noise levels when shopping.
What is the quietest sone rating available?
The quietest bathroom and ventilation fans are rated around 0.3 sones (approximately 25 dB). These premium fans are virtually silent during operation and are ideal for noise-sensitive environments like bedrooms or recording studios.
Should I choose a fan based on sones or CFM?
Consider both ratings. CFM (cubic feet per minute) measures airflow capacity – you need adequate CFM for your room size. Sones measure noise. First determine the CFM you need, then compare sone ratings among fans with similar CFM to find the quietest option.
How do I convert decibels to sones?
Use the formula: sones = 10^((dB – 40) / 33.22). For example, 50 dB = 10^((50-40)/33.22) = 10^0.301 = 2 sones. You can use the swap button in our converter to easily calculate dB to sones conversions.