Utility Calculators
Not every calculation is a major financial decision — sometimes you just need to know what 18% tip on $47 is, or how many square feet are in 12 square meters, or what a product's original price was before a 30% discount. This category collects all the "quick math" tools in one place so you can get an answer in under 10 seconds.
The percentage calculator goes well beyond simple percentage-of-a-number: it handles percentage change, reverse percentages, percentage error, and fraction conversions — 10 modes total with step-by-step solutions so you can see exactly how the result was reached. For shoppers, the discount calculator handles stacked discounts, BOGO deals, and sale price vs. original price lookups across 8 modes.
For freelancers and small business owners in the UK or anyone dealing with European-style VAT, the VAT calculator lets you add or remove tax at any rate, with a country picker covering 80+ jurisdictions. The unit converter bridges the imperial-metric gap that still trips up US travelers and anyone working with international specs — covering length, weight, temperature, area, and volume.
Tipping culture is strong in the US, and the tip calculator splits bills instantly between any number of people. Need to track billable hours? The time calculator adds, subtracts, multiplies, and converts durations across 7 modes — including a work-time breakdown and a multi-entry sum mode.
Featured Calculators
Percentage Calculator PRO
10 modes: basic %, change, reverse, fraction conversion, error — with step-by-step solutions.
FeaturedVAT Calculator PRO
Add or remove VAT, calculate from tax amount, margin VAT — 80+ country rates included.
FeaturedDiscount Calculator PRO
8 modes: % off, stacked discounts, BOGO, find original price, discount + tax combined.
FeaturedUnit Converter
Imperial to metric and back: length, weight, temperature, area, and volume conversions.
FeaturedTime Calculator PRO
Add, subtract, multiply durations — plus work-time breakdown and multi-entry sum with chart.
FeaturedTip Calculator
Calculate tip at any percentage and split the bill evenly between any number of people.
Fuel Cost Calculator
Calculate fuel costs for any trip based on distance and consumption.
Electricity Cost Calculator
Calculate how much an appliance costs to run per day, month, and year.
Heating Cost Calculator
Calculate annual heating costs based on area and fuel type.
Percentage Calculator PRO
Calculate percentages, percentage change, add or subtract percentages.
Tip Calculator
Calculate tips and split bills between multiple people.
VAT Calculator PRO
Add or remove VAT from any price quickly.
Discount Calculator PRO
Calculate sale prices and savings from percentage discounts.
Unit Converter
Convert between metric and imperial units for length, weight, temperature.
Time Calculator PRO
Add or subtract hours, minutes, and seconds easily.
Area Calculator
Calculate the area of rectangles, circles, triangles, and more.
Volume Calculator
Calculate volume of cubes, cylinders, spheres, cones, and more.
Concrete Calculator
Calculate how much concrete you need for your project.
Fraction Calculator
Add, subtract, multiply, and divide fractions.
Frequently Asked Questions
- What types of utility calculators are available?
- This category includes 13 free calculators for everyday math: a Percentage Calculator with 10 modes (basic percentage, percentage change, reverse percentage, fraction conversion, and more), a VAT Calculator supporting 80+ country tax rates, a Discount Calculator handling 8 scenarios including stacked discounts and BOGO deals, a Unit Converter for length, weight, temperature, area, and volume, a Time Calculator with 7 modes including work-time tracking, plus dedicated tools for tips, fuel costs, electricity costs, heating costs, area, volume, concrete, and fractions.
- How do percentage calculations work on Calculy?
- Our Percentage Calculator PRO offers 10 distinct modes to handle virtually any percentage question. The basic modes cover "what is X% of Y", "X is what percent of Y", and "percentage change between two values". Advanced modes include reverse percentage (finding the original value before a percentage was applied), percentage difference between two numbers, fraction-to-percentage conversion, and percentage error calculation. Each mode shows a step-by-step solution so you can understand the formula — not just the answer. This makes it useful for students, professionals, and anyone who wants to verify their math.
- Can I calculate VAT for different countries?
- Yes. The VAT Calculator includes a built-in country picker with current tax rates for over 80 countries worldwide. For the UK, it defaults to the standard 20% VAT rate. For EU countries, it covers standard and reduced rates. It supports five modes: adding VAT to a net price, removing VAT from a gross price, calculating from a known VAT amount, VAT on margin (used in second-hand goods), and invoice breakdown. For Spain, there is a special IVA + IRPF mode for freelancer invoices with professional withholding tax. All calculations update instantly as you type.
- What is the difference between the Time Calculator and the Date Calculator?
- The Time Calculator works with durations — hours, minutes, and seconds. Use it to add or subtract time spans (e.g., 2h 45m + 1h 30m), multiply or divide durations, sum multiple time entries for billing or timesheets, calculate work-time breakdowns, or convert between time units. The Date Calculator works with calendar dates — it adds or subtracts days from a specific date, finds the number of days (including working days) between two dates, and handles deadline math. In short: Time Calculator is for durations, Date Calculator is for calendar dates.