Transformer Sizing Calculator

Find the transformer kVA needed for a load.

Recommended size (kVA) 8.625

Formula: kVA = V·I ÷ 1000 × (1 + margin)

Step-by-step with your numbers:
1. Values used:
2. Load voltage = 230 V
3. Load current = 30 A
4. Safety margin = 25 %
5.
6. Recommended size = 8.625kVA
Did we solve your problem today?

Size a transformer with headroom above the expected load.

The math behind it

Load kVA = V·I ÷ 1000, then add a safety margin (typically 20–25%) for surges and growth.

Worked example

230 V, 30 A, 25% margin → about 8.6 kVA.

FAQ

Why oversize?

To handle startup surges, future loads and avoid running at full capacity continuously.