Calculators

Percentage, discount, rule of three, ethanol vs gasoline, compound interest, installments, fuel consumption, unit conversion, BBQ and party planning.

Everyday math: percentages, discounts, rule of three, fuel comparisons, compound interest, installments, and party-planning quantities.

Three percent helpers in one screen: percent of a value, ratio between two numbers, and percent change between before and after.

Type the original price and the discount percent to see the final price and savings, or compare two prices to learn the implied discount percent.

Type A, B and C and read X for direct proportions — common for school, recipes, paint coverage, and unit pricing.

Apply the classic 70% rule: if the ethanol price is below 70% of the gasoline price it is usually a better buy.

Combine a starting balance with regular monthly deposits and an annual rate to see total interest, contributions, and final balance.

Enter the financed amount, monthly interest rate and number of installments to read the fixed monthly payment, total paid, and total interest.

Pick a dimension, choose source and target units, and read the converted value with no network round trip.

Simple fields for adults, children, and appetite — instant estimates for meat, linguiça-style sausage, charcoal, ice, and soft drinks. Runs only in your browser.

Enter adults, children, hours, and whether you are serving snacks only or a meal — get starter numbers for cake, salgadinhos, and drinks.

Simulate months of compounding with separate monthly or annual rates for return, admin, and inflation — runs entirely in your browser.

Pizza Calculator locally in your tab — quick and privacy-friendly.