Common everyday tasks
Translate a sale percentage into savings and final price.
Open calculator Tip CalculatorSplit a tip and total across a party.
Open calculator Unit Price CalculatorCompare differently sized packages on one basis.
Open calculator Number to Words ConverterSpell out a check amount with the cents written as a fraction.
Open calculatorHow to use these calculators
Everyday calculations often look simple because the arithmetic is short. The decision can still go wrong when the base price, tax treatment, distance, fuel unit or service charge is unclear. Enter the amount exactly as it appears on the receipt, label or trip plan and check what the result includes.
A useful estimate separates facts from choices. The shelf price and sales-tax rate may be known, while a tip rate or future fuel price is a scenario. Run more than one scenario when the uncertain input could change the decision. Unit-price comparisons also require equal package units; a lower sticker price is not automatically a lower price per ounce or item.
Three checks that change the answer
Identify the base amount
Discount is normally applied before sales tax, while tipping customs vary by place and service.
Normalize the units
Compare ounce with ounce, item with item or mile with mile before choosing.
Use a range for uncertain costs
Fuel price, mileage and fees can change, so a low and high scenario is more informative than false precision.
Before you use the answer
- Check whether tax or fees are already included.
- Use the same package unit for both products.
- Confirm miles per gallon versus liters per 100 kilometers.
- Keep the receipt or source rate with the result.
Browse all 9 everyday calculators
Every tool calculates in your browser. Pages marked “Reviewed guide” also include topic-specific explanations and source checks.
- Percent Off CalculatorReviewed guideCalculate sale price, savings, tax and quantity total from a percentage discount.
- Mileage CalculatorReviewed guideTotal trip mileage, reimbursement, fuel use and fuel cost across repeated or round trips.
- Discount CalculatorReviewed guideSee the sale price and exactly how much you save, including an extra discount taken after the first one.
- Tip CalculatorReviewed guideCalculate a tip before or after tax and split the exact total across a group.
- Sales Tax CalculatorReviewed guideAdd a sales-tax rate to a pre-tax price.
- Unit Price CalculatorReviewed guideFind the price per unit of a package and compare two packages to see which is the better deal.
- Fuel Cost CalculatorReviewed guideEstimate the fuel and cost needed for a trip.
- Tire Size CalculatorReviewed guideCompare two metric tire sizes, diameter, circumference, revolutions and speedometer change.
- Number to Words ConverterReviewed guideWrite any number in words, spell out a check amount with cents as a fraction, or turn a number into ordinal words.
Frequently asked questions
Is sales tax calculated before or after a discount?
Rules and store practices vary, but many ordinary discounts reduce the taxable selling price. Check the receipt and local tax authority.
Does the tip calculator include tax?
It uses the bill amount you enter, so choose a pre-tax or after-tax base deliberately.
Why does fuel economy direction matter?
Miles per gallon rises with efficiency, while liters per 100 kilometers falls; they are inverse styles of measure.
Can unit price compare products of different quality?
It compares quantity and price only. Quality, waste, durability and delivery costs remain separate decisions.
Reference starting points
Individual reviewed guides cite the equation or standard used by that calculator. These authorities provide broader context for this collection.