Pull-Up & Always-On Load Calculator

Home › Calculators › Pull-Ups, and What a Load Costs Per Year

Supply voltage V

Pull-up resistance Ω

Or: a current you are willing to spend µA — gives a resistor

Seconds a day it is connected 86400 = always

Pack capacity mAh

Your sleep current mA, for comparison

Enter a supply and a resistance, then press Calculate.

From the book — Chapter 8. I = V ÷ R while connected. Cost over a year = I × the fraction of the year it is connected. Sizing from a budget: R = V ÷ I, rounded UP.

Chapter 8's connected-ness test, which is the most useful habit in the book. Everything stays in your browser — no sign-up, nothing stored.