Calculators

Calculate your exact age in years, months and days, plus total days lived and a countdown to your next birthday.

Find the sale price and how much you save from any percentage discount.

Add your appliances – fridge, AC, fans, lights, pump, iron – to find the running and starting watts and the generator size (kVA) you need, with a safety margin.

Calculate percentages easily: X% of Y, what percent X is of Y, percentage increase/decrease and difference.

Calculate the solar system size (kW), number of panels, roof area, cost and payback from your monthly electricity units.

Find the right air conditioner size in tons and BTU for your room based on area, ceiling height, sun exposure, people and kitchen – avoid buying too small or too big.

Add or subtract days, weeks, months or years from a date – with business days and day of the week.

Calculate the exact age difference between two people in years, months and days – for couples, siblings, friends or any two dates.

Calculate area and perimeter of squares, rectangles, circles, triangles, trapezoids and more.

Find the average (mean), median, mode, sum and range of any list of numbers.

Estimate how long a battery will last from its capacity (mAh or Ah), voltage and load current or watts – for power banks, UPS, solar, e-bikes and electronics projects.

Add, subtract, multiply and divide binary numbers, plus AND, OR, XOR and bit shifts – with decimal and hex results.

Calculate how many bricks, cement bags and sand you need for a wall – 4.5" and 9" walls, any brick size.

Calculate concrete volume plus cement bags, sand and crush for slabs, columns and footings (1:2:4, 1:1.5:3 mixes).

Count the days, weeks, months and years between two dates, including working days.

Find what day of the week any date falls on – past or future – plus the day of the year, week number and how many days from today.

Convert your dog’s age to human years using size-based vet charts and the 2020 epigenetic clock formula.

Estimate your monthly electricity bill and units (kWh) from your appliances and usage hours.

Calculate your car or bike fuel average (km per litre) from odometer readings, plus cost per km.

Estimate fuel cost for any trip from distance, mileage (km/l) and petrol price.

Calculate total hours worked from start and end times with breaks, overtime and pay.

Find the right current-limiting resistor for an LED (or several in series) from supply voltage, LED forward voltage and current – with nearest standard resistor value and wattage.

Calculate how much paint you need for a room – walls, ceiling, doors, windows and number of coats.

Estimate cement bags and sand needed for wall or ceiling plaster – choose area, thickness and mix ratio (1:4, 1:5, 1:6) for an accurate material list.

Solve ratios and proportions (A:B = C:D), simplify ratios and scale recipes or images.

Calculate roof pitch (x/12), angle in degrees, slope %, rafter length and roof area from rise and run – or from angle. For builders, DIY and sheet-roof planning.

Calculate speed, distance or travel time – in km, miles, km/h, mph and m/s. Great for trips and physics homework.

Calculate square feet, square metres, marla and gaz for rooms, plots and floors – add several rooms or shapes and get the total area and flooring cost.

Design comfortable, code-friendly stairs – enter total floor-to-floor height and get number of steps, riser height, tread depth, total run, stringer length and angle.

Calculate the weight of steel rebar (sariya) by diameter and length using the D²/162 formula – total kg, tons, and bars per ton for 8mm to 32mm bars.

Calculate how many tiles and boxes you need for a floor or wall, including grout gap and wastage.

Add or subtract hours, minutes and seconds and convert the result to decimal hours.

Calculate the tip and split the restaurant bill between friends in seconds.

Decode a tyre size like 185/65 R15 – diameter, sidewall height, circumference – and compare two sizes to see the speedometer difference before changing tyres or rims.

Calculate UPS or inverter battery backup time from your load, battery Ah and battery type – for load-shedding planning.

Compare prices of different pack sizes and find the best deal – price per kg, litre, piece or 100 g.

Calculate voltage drop, end voltage and power loss in a cable from its size, length, material and current – single-phase, three-phase or DC (solar).

Find how many litres or gallons a rectangular or round water tank holds – enter dimensions in feet, inches, metres or cm and see capacity plus filled amount.

Convert watts to amps and amps to watts for DC, single-phase AC and three-phase AC – with voltage and power factor – plus the right breaker size.

Find the right copper or aluminium cable size (mm² / AWG) for a load in amps or watts, cable length and allowed voltage drop – for home wiring, solar and ACs.

Count working (business) days between two dates, excluding weekends and your holidays – or add working days to a date to find a deadline. Choose Sat-Sun, Fri-Sat or Sunday-only weekends.

Convert between kVA, kW and amps for single-phase and three-phase supplies with power factor – for sizing generators, UPS, transformers and cables.