PenniTools Calculator Guides

Simple explanations, formulas and examples to help you use everyday calculators with confidence.

Learn the formula, then use the calculator

These guides explain common calculations in plain language, show sample numbers and link directly to the matching PenniTools calculators. They are designed for quick checks when planning travel, construction, vehicle running costs or personal finance.

Road Trip Cost Guide

Estimate fuel, tolls, total travel expense and cost per person for an India road trip.

Fuel & Mileage Guide

Understand km/L, fuel required, fuel cost and how to calculate vehicle mileage.

Square Feet & Area Guide

Calculate room, floor and construction area from feet, inches and metric measurements.

EMI Calculator Guide

Learn how loan amount, interest rate and tenure affect monthly EMI and total repayment.

GST Calculator Guide

Calculate GST, GST-inclusive prices and GST-exclusive amounts with clear examples.