Future Value Calculator
Estimate how a starting balance can grow with compound interest and monthly contributions.
Tools
Tools
Choose a tool, fill in the fields and generate the result. Pages are short, clear and focused on the task.
Profit Margin Calculator
Calculate gross profit, profit margin, markup and selling price from your cost and pricing target.
Percent Error Calculator
Calculate percent error, relative error, absolute error and raw difference between an observed value and a reference value.
Half-Life Calculator
Estimate the remaining amount after half-life decay and see the remaining percentage instantly.
Speed Calculator
Calculate average speed, pace per kilometer and conversions between km/h, m/s and mph.
Online QR Code Generator
Create QR codes for links, text, email, phone, SMS and Wi-Fi with adjustable size, margin and colors.
TDEE Calculator: estimate daily calories
Estimate your daily energy expenditure and compare maintenance, deficit and lean bulk targets.
Sample Size Calculator
Estimate how many responses you need for a survey, poll or study using margin of error and confidence level.
Pythagorean Theorem Calculator
Find a missing leg or hypotenuse, plus triangle area and perimeter, from any two sides of a right triangle.
Nether ↔ Overworld Coordinate Converter
Convert Minecraft X and Z coordinates between the Nether and the Overworld with the 8:1 portal ratio.
Square Footage Calculator
Calculate square footage for rooms, flooring, yards, lots and simple layout projects.
Time Duration Calculator
Add or subtract days, hours, minutes and seconds and convert the result instantly.
Loan Payment Calculator
Estimate payment amount, total interest, overall cost and extra-payment savings on a fixed-rate loan.
Calorie Calculator
Estimate maintenance calories, deficit targets or surplus targets from your body data and activity level.
Quadratic Formula Calculator
Find the discriminant, real or complex roots, vertex, and axis of symmetry for ax² + bx + c.
Simple Interest Calculator
Calculate simple interest, period rate and total amount from principal, annual rate and time.
Mortgage Calculator
Estimate loan amount, monthly payment, total interest and full housing cost with taxes, insurance and fees.
Discount Calculator
Work out sale price, amount saved, discount rate and original price in one place.
Add Days to Date Calculator
Add or subtract days and see the new date, weekday and ISO week instantly.
IP Subnet Calculator
Calculate network address, broadcast, host range, subnet mask and CIDR from an IPv4.
GPA Calculator
Calculate weighted GPA, unweighted GPA and grade averages with course credits.
Final Grade Calculator
See what score you need on your final exam to reach your target course grade.
Bulk Broken Link Checker
Check many links in the browser and flag URLs with errors, redirects or blocked responses.
Age Calculator
Calculate exact age in years, months and days from a birth date.
Z-Score Calculator
Calculate z-score, approximate percentile and standard-deviation distance from the mean.
Mean, Median, Mode and Range Calculator
Calculate mean, median, mode, range and core descriptive stats from a list of numbers.
Time Zone Calculator
Convert a time between zones and check the date shift before you schedule anything.
Random Number Generator
Generate random integers with a custom range, quantity, repeat control and output order.
Day of Week Calculator
Find the weekday for any date and see the ISO week, day of year and days left in the year.
Tip Calculator
Calculate tip amount, bill total and per-person cost with a custom percentage.
How to choose the right tool
Use search when you already know the task name and browse tags when you want to compare similar options. Public pages are organized for quick decisions, review and small workflows.
What to check before picking one
Check whether the tool matches the unit, format or context of your task. When more than one option looks similar, compare the summary, fields and related links before you commit to one.