Built for the field
A clean, high-contrast interface designed for quick use on active job sites.
Electrical calculators for the field
Sparky Toolbox
Stop wasting time with manual paperwork or complex formulas. Sparky Toolbox gives electrical contractors and field electricians fast preliminary calculations right from a phone.
Built for busy job sites
9 essential calculators
Fast preliminary estimates
Electrical planning articles
Fast estimates
Generate quick preliminary calculations to speed up project bidding and field checks.
Lightweight and fast
Open the app quickly when every minute on the job matters.
9 calculators in one app
Tools for estimating, bidding, and field verification
Ohms Law
Instantly solve for voltage, current, and power.
Motor OCPD & Wire Sizing
Determine overcurrent protection devices and wire sizes for motors.
Transformer OCPD & Wire Sizing
Get breaker and conductor sizing for transformer loads.
Wire Selection & Sizing
Select wire size and matching OCPD for specific applications.
Conduit Fill
Check total wire capacity limits for conduit runs.
Voltage Drop
Estimate voltage loss over long distances to keep systems efficient.
Standard Dwelling Load
Simplify residential service calculations in seconds.
Transformer Sizing
Determine the kVA rating needed for a specific load.
Solar Panel Calculator
Input energy targets to estimate how many PV panels you need.
Why electricians love this app
Put a full suite of electrical tools in your pocket
Whether you are estimating a project, bidding a job, or verifying field measurements, Sparky Toolbox streamlines the calculations that slow down the day.