Free online calculators
Percentages, VAT, zakat, dates and working days, unit and currency conversion, early loan settlement, admission score, calorie and water needs, and a bill split. No sign-up and no adverts.
- Pregnancy Due Date Calculator — Work out an estimated due date from your last period, the date of conception, or an IVF transfer — and see how many weeks and days along you are, which trimester that is, and every date in between. It adjusts for a cycle that is not 28 days, and gives every date in the Hijri calendar as well as the Gregorian one. Nothing is sent anywhere.
- Percentage Calculator — Answer the common percentage questions instantly: what is X% of Y, X is what percent of Y, and the percentage increase or decrease from one number to another. Runs entirely in your browser.
- Bill Splitter — Split a restaurant or group bill fairly: add an optional tip percentage, set how many people are paying, and see the per-person share and the grand total. Runs entirely in your browser.
- Pomodoro Timer — A distraction-free Pomodoro timer: work in focused sprints, take short and long breaks, and let it cycle automatically with a gentle chime and a round counter. Custom lengths are remembered on your device. Runs entirely in your browser.
- Age Calculator — Enter a birth date to see the exact age in years, months and days, the totals in months, weeks and days, the weekday you were born on, and a countdown to the next birthday. Runs entirely in your browser.
- Working Days Calculator — Count the working days between two dates, excluding the weekend — Friday–Saturday for Saudi Arabia or Saturday–Sunday elsewhere — with totals for calendar days and weekend days. Runs entirely in your browser.
- Countdown Timer — Set a target date and time — a deadline, launch, trip or celebration — and watch a live countdown of days, hours, minutes and seconds tick down. Your event is remembered on this device. Runs entirely in your browser.
- VAT Calculator — Add or remove Saudi VAT (15% default, 5%/0% presets) — net, VAT and gross in SAR to the halala, with a copyable breakdown. Bilingual, in-browser.
- Unit Converter — Convert length, mass, temperature, data, area, volume, speed and time — live, with swap + copy. Exact tables; temperature with proper offsets.
- Currency Converter — Convert between the Saudi Riyal and world currencies at up-to-date daily reference rates — swap direction in a tap. Rates from a free public feed, cached for offline use; your amounts never leave your browser.
- Date Diff — Find the exact duration between two dates — years, months, days, plus total days and weeks. Runs entirely in your browser.
- Tap BPM — Find a track’s tempo by tapping along. It averages over a sliding window so it follows a tempo change instead of burying it, and it tells you how steady your tapping was. It also gives the quarter, eighth and dotted-eighth times in milliseconds, which is what a delay pedal wants.
- Sound Level Meter — A live level meter using your microphone, with a running graph and peak hold. It shows relative loudness in dBFS, not calibrated decibels — a browser cannot know which microphone it is behind or what gain the system applied. Good for comparing two rooms; not for judging whether a workplace is safe.
- Blood Sugar Converter — Convert a blood glucose reading between mg/dL and mmol/L, and HbA1c between % and mmol/mol, with the estimated average glucose. Saudi labs report mg/dL while most research uses mmol/L, and the factor between them is 18. It says where a reading falls and flags one low or high enough to need acting on now.
- Sleep Cycle Calculator — Work backwards from when you need to be up, or forwards from now, to the times that land at the end of a ~90-minute sleep cycle rather than mid deep sleep. Allows for the time it takes to fall asleep, shows Fajr, and marks the last third of the night for qiyām.
- Water Intake Calculator — Work out a day’s water from your body weight, then add what the heat, your activity and time in the sun actually cost — because “eight glasses a day” describes a mild climate and says nothing about a Riyadh summer. Shows how the total is made up and how to fit it between iftar and suhoor.
- Medicine Timing Planner — Spread doses evenly across your waking day, or across the window between iftar and suhoor — about ten hours rather than twenty-four. Each dose is anchored to the nearest prayer, easier to remember than a clock time, and it warns when four doses will not fit comfortably in a fasting night.
- Sunrise, Sunset & Golden Hour — Sunrise, sunset, solar noon, the three twilights, and the golden and blue hours for any place and date — computed from the sun’s actual altitude rather than a rule of thumb like “an hour after sunrise”. Shows the Hijri date and prayer times for the same spot.
- Coordinate Converter — Paste coordinates in any common form — decimal, degrees-minutes-seconds, or degrees and decimal minutes — and get every other form back, including UTM and MGRS for survey and field maps. Add a second point for the distance and bearing between them.
- Time Zone Planner — Add the places your people are in and see the whole day at once, colour-coded by whether each hour lands in working hours, at the edges, or in the middle of the night. It ranks the best slots for everyone, with daylight saving on the chosen date already handled.
- Calorie & BMI Calculator — Work out how much you actually burn in a day and what to eat for your goal — resting burn, total daily burn, a calorie target for losing, holding or gaining, and a reasonable protein/carb/fat split, plus your BMI and healthy weight range. Uses Mifflin-St Jeor, which measures closest to reality.
- Stopwatch & Timer — A stopwatch with laps and a countdown timer with an alarm, in one place. Both take their time from the clock rather than by counting ticks, so switching tabs, locking the phone or leaving it in the background does not lose the minutes in between — which is what usually goes wrong with a timer in a browser.