← All tool categories
49 working tools

Everyday Calculators

Solve practical percentage, statistics, fuel and planning calculations locally.

Percentage Calculator

calculate a percentage of a value, percentage change, reverse percentage and increase or decrease scenarios.

Open tool β†’

Secure Random Number Generator

generate unbiased cryptographically secure integers inside a chosen inclusive range.

Open tool β†’

Arithmetic Mean Calculator

calculate count, sum, arithmetic mean, minimum and maximum from a pasted number list.

Open tool β†’

Geometric Mean Calculator

calculate the geometric mean of positive values using logarithms to avoid avoidable overflow.

Open tool β†’

Fuel Consumption Calculator

convert trip distance and fuel used into L/100 km, km/L, US MPG and imperial MPG.

Open tool β†’

Date Duration Calculator

calculate signed elapsed days, hours, minutes and seconds between two local date-time values.

Open tool β†’

ISO Week Date Calculator

convert a calendar date to its ISO week-year, week number and weekday without timezone ambiguity.

Open tool β†’

Business Days Calculator

count Monday-through-Friday dates between two calendar dates with a clearly stated no-holiday rule.

Open tool β†’

Calendar Quarter Calculator

identify the calendar quarter for a date, UTC-safe boundaries and elapsed or remaining days.

Open tool β†’

Month Calendar Generator

generate a copyable monthly calendar with Monday-first or Sunday-first weekday ordering.

Open tool β†’

Day of Year Calculator

calculate the ordinal day, days remaining and leap-year status for a calendar date.

Open tool β†’

Weekday Occurrence Calculator

list every occurrence of a selected weekday within a calendar month using UTC-safe dates.

Open tool β†’

Timezone Offset Converter

convert a wall-clock date and time between explicit UTC offsets without external timezone data.

Open tool β†’

Date Offset Calculator

add or subtract days, weeks, months or years with UTC-safe validation and month-end clamping.

Open tool β†’

Date Midpoint Calculator

calculate the exact UTC midpoint between two validated dates and times.

Open tool β†’

Date Interval Overlap Calculator

calculate the exact overlap or gap between two validated UTC date-time intervals.

Open tool β†’

Recurring Date Generator

generate a bounded sequence of UTC dates at a fixed daily or weekly interval.

Open tool β†’

Nearest Weekday Calculator

move a weekend date to the nearest, previous or next Monday-through-Friday date.

Open tool β†’

Month Boundary Calculator

find the first day, last day and day count for the month containing a validated UTC date.

Open tool β†’

Simple Interest Calculator

Calculate principal interest and final balance using a transparent non-compounding formula.

Open tool β†’

Compound Interest Calculator

Calculate compound growth from principal, annual rate, years and compounding frequency.

Open tool β†’

Loan Payment Calculator

Estimate a fixed periodic loan payment from principal, annual rate and term length.

Open tool β†’

Return on Investment Calculator

Calculate absolute gain and return on investment percentage from cost and final value.

Open tool β†’

Profit Margin Calculator

Calculate gross profit and margin percentage from revenue and total cost values.

Open tool β†’