Resistora API

Programmatic access to all Resistora tools. Integrate resistor combination finding, circuit calculation, and voltage divider design into your applications.

PRO Plan Required

API Documentation

Interactive API documentation with request/response examples

Swagger UI Scalar Docs

Both link to the same OpenAPI spec — choose whichever UI you prefer.

Getting Started

Three steps to start using the API

1
Create an account
Register for a Resistora account and upgrade to the PRO plan.
2
Generate an API token
Go to your Account page and generate an API token.
3
Make API requests
Include your token in the X-API-Key header and follow the API documentation for endpoint details.

Available Features

Resistor Combination

Find optimal resistor combinations from your available resistors (2–4 resistors)

Resistor Combination (Pro)

Advanced genetic algorithm solver for complex combinations (2–6 resistors, PRO only)

E-Series Finder

Find resistor combinations from standard E-series (E6–E192)

Voltage Divider

Design voltage divider circuits with optimal resistor pairs

Divider Builder

Calculate output voltage for a given voltage divider configuration

Circuit Calculator

Calculate total resistance for custom circuit schemas (up to 10 schemas)

Circuit Builder

Calculate resistance for a single circuit schema with given resistor values

Rate Limits

PRO Plan Limits

Per-feature rate limits for API access

Feature	RPM	Daily	Monthly
Resistor Combination	30	500	5,000
Resistor Combination (Pro)	10	100	1,000
E-Series Finder	30	500	5,000
Voltage Divider	10	100	1,000
Divider Builder	100	1,000	Unlimited
Circuit Calculator	100	1,000	Unlimited
Circuit Builder	100	1,000	Unlimited