Half-value layers to millimeters of lead
Type a value in HVL to get it in mm Pb instantly.
26.7mm Pb
That's about the same as a shielded wall. About 12.5% of the radiation still gets through.
Convert the other way: mm Pb to HVL
What it means
How much gets stopped?
Thicknesses are for a 1 MeV gamma beam. Half-value layers change with photon energy, so a shield that works for one isotope may not for another.
The math
How to convert HVL to mm Pb
To convert half-value layers to millimeters of lead, multiply by 8.9.
Example: 3 HVL × 8.9 = 26.7 mm Pb.
In the other direction, 1 mm Pb = 0.11236 HVL.
Every unit
Your shielding in every unit
Tables
HVL to mm Pb conversion table
| HVL | mm Pb |
|---|---|
| 0.5 HVL | 4.45 mm Pb |
| 1 HVL | 8.9 mm Pb |
| 2 HVL | 17.8 mm Pb |
| 3 HVL | 26.7 mm Pb |
| 4 HVL | 35.6 mm Pb |
| 5 HVL | 44.5 mm Pb |
| 7 HVL | 62.3 mm Pb |
| 10 HVL | 89 mm Pb |
| 13 HVL | 115.7 mm Pb |
| 20 HVL | 178 mm Pb |
mm Pb to HVL conversion table
| mm Pb | HVL |
|---|---|
| 0.5 mm Pb | 0.0561798 HVL |
| 1 mm Pb | 0.11236 HVL |
| 2 mm Pb | 0.224719 HVL |
| 3 mm Pb | 0.337079 HVL |
| 4 mm Pb | 0.449438 HVL |
| 5 mm Pb | 0.561798 HVL |
| 7 mm Pb | 0.786517 HVL |
| 10 mm Pb | 1.1236 HVL |
| 13 mm Pb | 1.46067 HVL |
| 20 mm Pb | 2.24719 HVL |
Quick answers
Quick answers
- How many mm Pb is 1 HVL?
- 1 HVL is 8.9 mm Pb.
- How many mm Pb is 10 HVL?
- 10 HVL is 89 mm Pb.
- How many mm Pb is 3 HVL?
- 3 HVL is 26.7 mm Pb.
The units
About these units
Half-value layers (HVL)
How many halvings the beam has been through.
Millimeters of lead (mm Pb)
Real lead thickness, for a 1 MeV gamma beam.
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