Guides & Tutorials
Step-by-step guides on how to calculate, convert and work with numbers, text and developer tools.
How to Calculate a Percentage: Formula and Examples
Learn how to calculate a percentage step by step with the formula, real examples and a free calculator.
How to Calculate a Discount: Final Price and Savings
Learn how to calculate the final price and savings of a discount, with formulas, examples and a free calculator.
How to Calculate VAT: Add and Extract
Learn how to add VAT to a price or extract it from a total, with rates and a free calculator.
How to Count Words: Tips and Tools
Learn how to count words and characters in a text, how many words per page and the best free tools.
How to Calculate the Reading Time of a Text
Learn how to calculate how many minutes it takes to read a text based on average reading speed (words per minute).
What is a SHA-256 Hash: How It Works and Uses
Learn what the SHA-256 hash is, how it works, where it is used (integrity, passwords, blockchain) and how to generate it for free.
What is a UUID: Definition, Format and Uses
Learn what a UUID is, its 128-bit format, what it is used for and how to generate them for free and securely.
How to Convert Units: Length, Weight and Temperature
Learn how to convert between meters and feet, kilograms and pounds, Celsius and Fahrenheit, with formulas and a free converter.
How to Calculate a Tip: Standard Percentages and Bill Split
Learn how to calculate a restaurant or service tip with standard percentages and how to split the bill among several people.
How to Calculate BMI: Formula, Chart and Examples
Learn how to calculate your Body Mass Index with the formula, the category chart and practical examples.
How to Calculate Net Salary from Gross: IRPF and Social Security
Learn how to calculate your net salary from gross in Spain: what is deducted, how IRPF works and Social Security.
How to Convert Currencies: Exchange Rates and Currencies
Learn how to convert currencies and understand exchange rates between the world's main currencies.
How to Calculate Compound Interest: Formula and Examples
Learn how to calculate compound interest with the formula, practical examples and an investment calculator.
How to Calculate a Mortgage Payment: Formula and Examples
Learn how to calculate your monthly mortgage payment with the French method formula, real examples and a free calculator.
How to Calculate IRPF: Tax Brackets, Deductions and Examples
Learn how to calculate IRPF in Spain: state brackets, personal allowance, deductible expenses and a free calculator.
How to Calculate Unemployment Benefits in Spain
Learn how to calculate your unemployment benefit: duration, percentage based on regulatory base and how much you will receive per month.
How to Calculate Retirement Pension in Spain
Learn how to calculate your retirement pension: regulatory base, percentage by years contributed and minimum pension.