Calculated using IPC-2221B Table 6-1 Electrical Conductor Spacing.

Note on Voltage: The voltage used should be the maximum Peak AC or DC voltage across the conductors.

For voltages > 500V, the clearance scales linearly according to the standard's per-volt multiplier:

• B1 (Internal): $0.25 mm + 0.0025 \times (V - 500)$
• B2 (Ext Uncoated): $2.5 mm + 0.0050 \times (V - 500)$
• B4 (Ext Coated): $0.8 mm + 0.00305 \times (V - 500)$

This standard is widely used for general electronics. Mains-connected or safety-critical isolation (creepage) often requires IEC 60950-1 or UL 62368-1, which are significantly more stringent.