Useful tools
Calculate costs, convert measurements, and compare options. Enter your numbers and see how the result was calculated.
Featured utility
Check whether a website responds from your browser and see what the browser can learn about the request. It runs in your browser and explains when a site hides details from browser-based checks.
Compare prices, estimate payments, and understand everyday financial tradeoffs.
Money
Calculate a tip, total bill, and per-person share while seeing the math behind the result.
Enter the bill, tip percentage, and group size to see the total and each person's share. This tool does not calculate sales tax.
Open calculatorMoney
Find the sale price and total savings, including optional stacked discounts and sales tax.
Useful for checking a sale price before checkout and understanding whether multiple discounts are applied one after another.
Open calculatorMoney
Compare package prices by ounce, fluid ounce, metric quantity, or individual item.
Normalize different package sizes and units so you can compare the actual cost of what you are buying.
Compare optionsMoney
Estimate a payoff date, total interest, and how much time an extra monthly payment could save.
Compare your current payment with an accelerated plan and see how additional money changes the payoff timeline.
Open calculatorMoney
Calculate a monthly savings target or estimate when regular contributions could reach a goal.
Work backward from a target amount and date, with optional interest included when your account earns a return.
Open calculatorMoney
Compare simple and compound interest, effective annual yield, and year-by-year balances.
See how principal, rate, time, and compounding frequency change the balance instead of relying on a single headline number.
Open calculatorMoney
Add sales tax, remove tax from a total, or find the effective rate with each formula explained.
Use it when a posted price excludes tax, when you need to separate tax from a receipt total, or when checking a quoted rate.
Open calculatorMoney
Solve common percentage questions, percentage change, and increases or decreases with the formulas shown.
Handle everyday comparisons such as discounts, markups, growth, reductions, and the percentage represented by one value of another.
Open calculatorMoney
Estimate fixed monthly principal and interest, total interest, and an amortization schedule.
Explore how loan amount, rate, term, and optional extra costs affect the payment and the total paid over time.
Open calculatorMoney
Estimate fuel needed, trip cost, cost per mile, and each traveler’s share using your own route and vehicle values.
Adjust distance, fuel economy, fuel price, and passengers to create a transparent trip estimate for driving or moving.
Open calculatorPlan moving costs, compare quotes, and estimate packing supplies before moving day.
Moving
Build an itemized moving budget with transportation, travel, setup costs, and a contingency cushion.
Combine known quotes with your own estimates for fuel, lodging, packing, storage, cleaning, and the costs that appear late in a move.
Open estimatorMoving
Compare up to three moving quotes side by side, including fees, services, coverage, and contingency-adjusted totals.
Put competing estimates into the same format so missing services, extra fees, and different coverage levels are easier to spot.
Compare optionsMoving
Estimate boxes and packing supplies by room, then add your own prices for a private packing-supply budget.
Choose rooms and packing intensity to create a starting shopping list without sending your inventory or prices to a server.
Open estimatorMeasure time between dates and answer calendar-based planning questions.
Dates
Calculate age in calendar years, months, and days for today or another date.
Use a custom comparison date for planning, forms, milestones, or understanding how calendar-based age is counted.
Open calculatorDates
Measure the calendar time and weekdays between two dates with clear counting rules.
Compare elapsed days, weeks, months, and weekdays. The weekday count does not account for public holidays.
Open calculatorEstimate materials, household costs, and recipe quantities with visible assumptions.
Home
Estimate paint for a room or wall with coats, openings, coverage, and waste included.
Account for doors, windows, multiple coats, and a practical waste allowance before buying paint.
Open calculatorHome
Estimate volume, concrete bags, or gravel weight for rectangular and circular projects.
Switch between U.S. and metric measurements, include waste, and use editable bag yield or gravel density assumptions.
Open calculatorHome
Estimate appliance energy use and cost by day, month, and year from watts, usage time, and your rate.
Compare appliances using your own electricity rate without pretending to model every utility’s taxes, fees, or tier rules.
Open calculatorHome
Scale ingredient quantities up or down for a different number of servings while preserving the original ratio.
Enter the original serving count and the desired count to resize every ingredient consistently.
Open calculatorExplore educational estimates for calories, macros, and activity pace.
Health
Estimate resting needs, daily maintenance calories, and practical goal ranges.
Review the formula inputs and activity assumption behind the estimate; it is a planning aid, not medical advice.
Open calculatorHealth
Turn a calorie target and macro split into daily protein, carbohydrate, and fat grams.
Start with a calorie target and adjust the percentage split to see the corresponding daily gram targets.
Open calculatorHealth
Calculate pace, speed, or finish time for walking, running, cycling, and other distance activities.
Calculate pace and speed from distance and time, or estimate finish time from distance and a target pace.
Open calculatorWork through voltage, current, resistance, batteries, and component values.
Electronics
Calculate voltage, current, resistance, and power while following the formulas.
Enter any two known electrical values to solve for the third and see the resulting power in a low-voltage educational context.
Open calculatorElectronics
Estimate battery runtime from voltage, capacity, usable energy, load, and conversion losses.
Adjust usable capacity and efficiency so the estimate reflects the difference between ideal battery energy and real-world load.
Open calculatorElectronics
Decode 4-band, 5-band, and 6-band resistor values, tolerance, and temperature coefficient.
Select each color band to identify resistance, tolerance, and the temperature coefficient where a six-band code provides one.
Open calculatorElectronics
Calculate divider output, current, resistor power, and the effect of an optional load.
See how resistor values set the output and why a connected load can pull a divider away from its no-load voltage.
Open calculatorConvert common units and keep length, area, volume, mass, and temperature distinct.
Measurement
Convert common length, mass, volume, and temperature measurements between U.S. customary and metric units.
Choose a measurement type and units to see the conversion, the formula used, and a reminder about what the units describe.
Open converterUse focused browser tools for practical checks that do not belong to one subject hub.
Utilities
Check whether a website responds from your browser and see what the browser can learn about the request.
Check whether your browser can reach a URL. DNS lookups send the hostname to Cloudflare's public DNS service; the browser also contacts the website you enter. The URL is not sent to our server by this tool.
Test a website