Available Math Tools
Percentage Calculator
Quickly find what percent one number is of another, calculate percentage increase or decrease, and more.
Date Calculator
Calculate the number of days between two dates, or add/subtract days, weeks, months, or years from a date.
Tip Calculator
Calculate tip amounts, split bills among friends, and find the total per person with tax included.
Universal Unit Converter
Convert between units of length, weight, temperature, volume, speed, digital data, area, and pressure instantly.
Everyday Mathematical Relationships & Percentages
From shopping discounts and sales tax to loan amortization and unit conversions, percentage math forms the foundation of daily problem-solving.
Percentage Increase & Decrease
To find the percentage change between an old value and a new value, subtract the old value from the new value, divide by the absolute value of the old value, and multiply by 100: Change % = ((New - Old) / Old) * 100.
Dimensional Analysis & Unit Conversions
Converting between metric and imperial systems requires exact conversion factors (such as 1 inch = 2.54 cm, 1 pound = 0.453592 kg, and 1 gallon = 3.78541 liters) to maintain precision across scientific, culinary, and technical applications.