Copper Weight to Thickness
t = oz × 35 µm
Quick answer
This calculator solves t_µm = oz × 35 for Copper Thickness. With Copper Weight (oz/ft²) 0.5, the result is 0.0175 mm. It solves in 2 directions, so you can enter the values you have and get the one you need.
Calculator
Formula
Description
PCB copper thickness is traditionally specified in ounces per square foot (oz/ft²). One ounce of copper spread over one square foot gives a thickness of approximately 35 µm (1.37 mils). This is the standard unit used by PCB manufacturers worldwide. Common weights are 0.5 oz (17.5 µm), 1 oz (35 µm), and 2 oz (70 µm). Heavier copper (3-6 oz) is used for high-current power circuits. The result is in meters (base SI unit); use the unit selector to view in mm or µm.
Variables
- t — Copper thickness (m, display in µm)
- oz — Copper weight in oz/ft²
Practical Notes
Standard PCB copper weights: 0.5 oz (17.5 µm) for HDI and fine-pitch, 1 oz (35 µm) most common default, 2 oz (70 µm) for power circuits, 3 oz (105 µm) and higher for high-current applications. Plating adds additional copper: typical via plating is 20-25 µm. The minimum trace width for a given current depends directly on copper thickness — thicker copper allows narrower traces for the same current capacity.
Symbols and units
| Symbol | Meaning | Default unit | Accepted units |
|---|---|---|---|
| t | Copper Thickness | mm | mm, cm, m, km |
| oz | Copper Weight (oz/ft²) | — | — |
Step by step
- 1. What you know: Copper Weight (oz/ft²) 0.5
- 2. The relation: t_µm = oz × 35
- 3. Substitute: oz = 0.5
- 4. Result: Copper Thickness = 0.0175 mm
Worked examples
Minimum range
Given: Copper Weight (oz/ft²) 0.025
Result: Copper Thickness = 8.75 × 10⁻⁴ mm
Low range
Given: Copper Weight (oz/ft²) 0.25
Result: Copper Thickness = 0.00875 mm
Typical
Given: Copper Weight (oz/ft²) 0.5
Result: Copper Thickness = 0.0175 mm
High range
Given: Copper Weight (oz/ft²) 0.8
Result: Copper Thickness = 0.028 mm
Maximum range
Given: Copper Weight (oz/ft²) 8
Result: Copper Thickness = 0.28 mm
Solving for each variable
Solve for Copper Thickness
Copper Weight (oz/ft²) 0.025 → 8.75 × 10⁻⁴ mm
Solve for Copper Weight (oz/ft²)
Copper Thickness 0.1 mm → 2.857
How Copper Thickness changes with Copper Weight (oz/ft²)
| Copper Weight (oz/ft²) (input) | Copper Thickness (result) |
|---|---|
| 0.05 | 0.00175 mm |
| 0.125 | 0.004375 mm |
| 0.25 | 0.00875 mm |
| 0.375 | 0.01312 mm |
| 0.5 | 0.0175 mm |
| 0.75 | 0.02625 mm |
| 1 | 0.035 mm |
| 2 | 0.07 mm |
| 3.5 | 0.1225 mm |
| 5 | 0.175 mm |
The same result in other units
| Unit | Value |
|---|---|
| mm | 0.0175 |
| cm | 0.00175 |
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<p><a href="https://vbatpower.com/formulas/copper-weight-thickness/">Copper Weight to Thickness</a> Calculator by vbatpower.com</p>Frequently asked questions
How do you calculate Copper Weight to Thickness?
Use t_µm = oz × 35. With Copper Weight (oz/ft²) 0.5, Copper Thickness works out to 0.0175 mm.
How do you calculate 1 oz copper thickness and 2716.394 sq mm of copper gives me what weight?
Rearrange for Copper Thickness: with Copper Weight (oz/ft²) 0.25, Copper Thickness is 0.00875 mm.
What is the formula for Copper Weight to Thickness?
The formula is t_µm = oz × 35. PCB copper thickness is traditionally specified in ounces per square foot (oz/ft²).
How do you find Copper Weight (oz/ft²) when you know the other values?
Rearrange for Copper Weight (oz/ft²): with Copper Thickness 0.1 mm, Copper Weight (oz/ft²) is 2.857.
What units does Copper Weight to Thickness use?
Copper Thickness is shown in mm, cm. Values are held in SI base units internally, so you can mix prefixes without converting by hand.
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