Commercial Load Calculator

Use this commercial load workflow for preliminary block-by-block load arithmetic when connected VA, demand factors, continuous multipliers, voltage, phase, and a comparison ampere value are known.

  • Updated August 22, 2026
Inputs
Load blocks

Enter one row for each user-defined load block. Demand and continuous factors are user assumptions, not table lookups.

Row 1
Row 2
Row 3
Row 4
Result

Formulas

  • Block demand VA = connected VA x demand factor percent / 100
  • Block continuous adder VA = block demand VA x (continuous multiplier percent / 100 - 1)
  • Adjusted load VA = sum of block demand VA + sum of block continuous adder VA
  • Line current = adjusted load VA / (phase multiplier x voltage)
  • Effective demand percent = adjusted load VA / connected load VA x 100
  • Entered capacity margin = entered capacity amps - line current

Use this calculator

Total user-entered commercial load blocks, apply entered demand and continuous factors, estimate adjusted VA, line current, effective demand percent, and entered-capacity margin.

Read the result

Review the calculated values with their displayed units and assumptions. The result is a planning aid for the stated inputs, not a final equipment or installation decision.

Check before final work

This commercial load estimate uses user-entered load blocks and factor assumptions. It does not apply NEC demand tables, classify occupancy, select feeders or services, or prove code compliance.

Related calculators

Continue with nearby electrical workflows that use the same field context.

FAQs

Does this apply commercial demand tables?

No. The demand factor is entered for each block. This page only performs transparent VA and current arithmetic.

What should go in a load block?

Use a load block for a user-defined group such as lighting, receptacles, HVAC, equipment, or another verified project category.

Can this size a feeder or service?

No. It compares the estimate with an entered ampere value, but final feeder or service sizing requires adopted-code, equipment, and utility review.