🎉 Free launch period — every calculator, every feature unlocked, no account needed, through mid-November 2026. PDF reports carry a watermark for everyone during this period.

Soft Starter Sizing Calculator

Screens a candidate soft starter's rated current against a motor's FLA once ambient temperature, altitude and duty-cycle derating are applied, plus a voltage-rating check.

AAJappsEngineering Calculation Report

Soft Starter Sizing Calculator

Generic manufacturer-typical temperature/altitude/duty derating rates — see About panel

Generated

For preliminary engineering use only — always verify results against project-specific standards and a qualified engineer's review before use in a real design.

Motor

A
V

Candidate soft starter

A
V

Installation conditions

°C
m

Soft starter sizing check

Temperature factor1.00
Altitude factor1.00
Duty factor1.00
Derated capacity105.0 A
Voltage rating adequateYes
Current capacity adequateYes
ADEQUATE ✓