Find BMI, payroll, mortgage, tip, percentage, and salary calculators in one place. Every tool runs locally in your browser—nothing is uploaded.
Calculate the exact difference between two dates in years, months, days, and total days using a clear calendar-based method.
Free average calculator: arithmetic mean, sum, count, min, max, and range from pasted lists—grades, budgets, or datasets. Private, instant, no signup.
Free bi-weekly payroll calculator — estimate take-home pay every two weeks based on hourly rate or annual salary, with optional tax and deduction estimates. No signup needed.
Calculate BMI from height and weight using metric or imperial units. See BMI category ranges and use it as a quick screening estimate.
Estimate body fat % with US Navy waist/neck/hip measurements or BMI method. Runs locally in your browser—never uploaded. Free for men and women.
Free break-even calculator — find break-even units and revenue from fixed costs, price, and variable cost. Includes contribution margin and targets. No signup.
Estimate daily calories using the Mifflin-St Jeor BMR formula and TDEE activity multipliers for maintenance, weight loss, or weight gain.
Estimate voluntary donations from income × percentage or a fixed amount. Simple giving math for budgeting—not tax advice.
Calculate combinations nCr = n!/(r!(n−r)!) for unordered selections. Enter n and r for instant browser-based results.
Free cost of living calculator — compare two cities and estimate equivalent salary using cost indices (and optional category weights). Runs locally. No signup.
Free discount calculator — compute sale price and savings from an original price and discount (percent or amount). Supports reverse discount. No signup.
Free electricity cost calculator: kWh = (watts ÷ 1000) × hours; cost = kWh × your $/kWh rate—stack appliances, peak/off-peak. Runs in your browser, no signup.
Calculate powers like a^b, negative exponents, and fractional exponents with clear results and quick examples like 2^3 = 8.
Calculate exact n! for 0 ≤ n ≤ 500 with BigInt. No upload—runs in your browser. Free factorial for combinatorics homework.
Free fraction calculator with steps: add, subtract, multiply, divide, simplify, and show mixed/decimal forms instantly. Fast, private, no signup.
Free freelance rate calculator — turn target income, business expenses, tax, and billable hours into a minimum hourly rate, with optional profit buffer and project price. No signup.
Free fuel cost calculator: trip fuel = distance ÷ MPG (or km × L/100km ÷ 100) × price per gallon or liter—round trip & buffer optional. Private, no signup.
Find the greatest common factor of two or more integers using the Euclidean algorithm and factor-method explanations.
Estimate zakat on gold from weight, karat purity, and current 24k price per gram—nisab uses 85g pure gold; 2.5% if above threshold. Market rates change. No signup.
Calculate weighted GPA from letter grades and credit hours on the 4.0 scale. No upload—runs in your browser. Free, instant semester GPA.
Calculate heart rate training zones from age or max HR using percentage-based ranges. Find fat burn, aerobic, and threshold zones.
Hourly to daily, weekly, monthly & yearly gross pay with overtime and job compare. No upload—runs in your browser. Free.
Estimate ideal weight using Devine, Robinson, Miller, and Hamwi formulas and compare the output range in one place.
Calculate the least common multiple of two or more integers with formula-based steps and prime factorization guidance.
Calculate lean body mass from body fat % or Boer, James, and Hume formulas. Runs locally in your browser—never uploaded. Free LBM & BMR estimates.
Free logarithm calculator: log base 10, natural log (ln), log₂, or any custom base b for positive x. Runs in your browser—never uploaded.
Estimate daily macros from BMR and TDEE, then split calories into protein, carbs, and fats for fat loss, maintenance, or muscle gain.
Free meal cost calculator: sum ingredient costs, scale servings, cost per plate. Business margin mode. Runs locally—never uploaded.
Compare mean, median, and mode from one dataset. See how each central-tendency measure describes your numbers when outliers or skew matter.
Free monthly budget calculator — track income and categorized expenses to see surplus/deficit and 50/30/20 splits. Plan savings targets. No signup.
Calculate overtime pay at 1.5× or 2× your hourly rate. Enter regular hours and overtime hours to see total earnings instantly. No signup required.
Estimate ovulation day and fertile window from last period date and cycle length with a simple cycle-based method.
Free online percentage calculator: what is X% of Y, what percent is X of Y, percent increase & decrease, percent change, percentage difference, and reverse percentages. Live results in your browser. No signup.
Calculate permutations nPr = n!/(n−r)! for ordered selections. Enter n and r for instant results in your browser.
Estimate pregnancy due date from the first day of your last menstrual period (LMP) with a simple 40-week calculation.
Prime checker, factorization (91 = 7×13), prime list to 500 & nth prime finder. Runs locally in your browser—no upload, no signup.
Calculate event probabilities: complements, P(A and B), and P(A or B) for independent events. Browser-based, instant results.
Free profit margin calculator — compute profit, margin %, and markup from cost and selling price, or find price for a target margin. Runs locally. No signup.
Estimate daily protein requirements based on body weight, activity level, and fitness goal. Results in grams per day and per meal.
Free ratio calculator: simplify ratios to lowest terms, compare two ratios for equivalence, and view decimal form. Runs in your browser. No signup.
Calculate running pace, speed, or finish time from distance and time. Convert between min/km and min/mile for any race distance.
Estimate take-home pay from salary using simplified tax brackets and standard deductions (US/UK/CA/AU + custom). Shows effective and marginal rates. No signup.
Convert salary to hourly, daily, weekly, and monthly pay using the 2,080-hour baseline, then adjust for weekly hours and PTO for a true hourly rate. No signup.
Use a scientific calculator for trigonometry, logarithms, powers, roots, and constants with DEG/RAD support and instant browser-based results.
Find the best bedtime or wake-up time based on 90-minute sleep cycles. Minimize sleep inertia by waking at the end of a cycle.
Calculate square roots, cube roots, and nth roots with decimal precision and simplified radical form for integers.
Calculate population or sample standard deviation, see variance, and understand dataset spread with a simple variance-to-standard-deviation workflow.
Convert daily step count to kilometers or miles using stride length. See how far 10,000 steps travels for your height.
Split total study hours across subjects, weeks, and study days—see per-subject totals, weekly load, and hours per study day. Runs in your browser. No signup.
Free time-and-a-half calculator — enter your regular hourly rate and overtime hours to calculate pay at 1.5× rate. Instant results for payroll and wage verification. No signup.
Free tip calculator — find tip amount, bill + tip total, and per-person share. Presets for common percentages (10%, 15%, 20%), custom %, and equal split. Runs in your browser. No signup.
Free unit price calculator: divide price by quantity to compare cost per unit across package sizes. Private, instant, no signup.
Estimate daily hydration using a weight-based formula with activity adjustments, then view results in liters, cups, and milliliters.
Calculate net hours worked from start time, end time, and unpaid breaks. Daily and weekly modes with decimal hours. Runs in your browser — no signup.
Estimate zakat from cash, metals, and assets minus short-term debts—nisab via 85g gold or 595g silver × your price per gram, then 2.5% if due. Rules vary. No signup.
Free online calculators for BMI, percentages, calories, salary, discounts, and more—results in your browser with no account and no data stored on servers.
Pick a calculator, enter your values, and get the answer in seconds.
No signup required · No data stored · Works on desktop and mobile
Online calculators solve common math, finance, health, and everyday problems—from percentages and discounts to BMI, work hours, and salary estimates—with instant, copyable results.
Online calculators are simple tools that turn a question into a clear numeric answer. Instead of doing manual arithmetic (and risking mistakes), you enter inputs and get a result instantly—often with breakdowns, formulas, and practical interpretations.
This calculators hub helps you find the right calculator quickly—whether you're calculating tips, discounts, percentages, BMI, GPA, work hours, overtime, or salary estimates.
Concise answers for common searches — definitions, steps, and comparisons.
Yes. Each calculator runs in your browser with JavaScript—no account, no upload, and no storage of your inputs on EverydayTools servers. Suitable for quick BMI, budget, or payroll estimates; not a substitute for clinical, tax, or legal advice.
Use the Bi-Weekly Payroll Calculator for hourly rate × hours × 2 plus overtime. For annual salary divided into pay periods, start with Salary to Hourly Calculator, then open the payroll tool that matches your schedule.
Select what you're solving: percentage, tip, discount, salary, BMI, GPA, or work-hours.
Type the values (amounts, rates, heights/weights, times). Use the exact units the calculator expects.
Review both the final answer and any intermediate values (like tax, overtime split, or percentage change).
Copy the number into a form, budget, quote, invoice, or plan.
Common real-world scenarios where this tool saves time.
Calculate discounts, markups, sales tax, and final prices quickly.
Estimate salary, savings goals, and percentage splits for budgets and bills.
Calculate BMI and related metrics for fitness plans and progress tracking.
Compute work hours, breaks, overtime, and estimated pay for timesheets.
Input
Original price: $120, Discount: 15%Output
$102 (you save $18)Great for shopping and pricing scenarios; shows both final price and savings.
Input
Bill: $46.50, Tip: 18%Output
$8.37 tip, $54.87 totalUse for restaurant bills, delivery orders, and split checks.
Input
Old: 80, New: 92Output
15% increaseUseful for growth metrics, KPI reporting, and price changes.
Most calculators follow standard formulas (percentages, ratios, rates) and return both a final value and a practical breakdown. For time-based calculators, times are converted to minutes first to avoid rounding errors, then returned as hh:mm and decimal hours.
| Category | Example tools | Typical question |
|---|---|---|
| Health | BMI, Calorie, Body Fat | What is my BMI or daily calories? |
| Finance | Mortgage, Break-even, Tip | What is my payment or margin? |
| Work | Bi-weekly pay, Overtime, Timesheet | What is my paycheck or hours? |
| Math | Percentage, GPA, Fraction | What is X% of Y? |
Likely cause: Unit mismatch or percentage entered in the wrong format.
Fix: Confirm units and whether the input expects percent (15) or decimal (0.15).
Likely cause: Overtime thresholds and rounding rules vary by employer and jurisdiction.
Fix: Use your company's policy for overtime and rounding, then compare against the calculator's breakdown.
Likely cause: Different sources use different cutoffs for age groups and populations.
Fix: Use BMI as a general indicator; consult a professional for medical interpretation.
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Yes—they're free with no signup and no usage limits.
All calculators use established, widely accepted formulas—for example, the Mifflin-St Jeor equation for calorie needs, the WHO BMI classification, and standard financial formulas for margin and markup. Results are as accurate as the values you enter. Health calculators give population-average estimates, not clinical diagnoses.
Formulas are deterministic; differences usually come from rounding, unit choice, or policy differences (like overtime/tax rules).
Yes. The calculators are responsive and work on mobile browsers.
Multiply the number by (percent ÷ 100). Example: 15% of 200 = (15 × 200) ÷ 100 = 30. The Percentage Calculator also covers percentage change, increase, and reverse percentage in one tool.
Percentage change = (new − old) ÷ old × 100. Example: 80→92 is (12÷80)×100 = 15%.
BMI (Body Mass Index) is your weight in kilograms divided by the square of your height in metres (kg/m²). It classifies weight status as underweight (below 18.5), healthy (18.5–24.9), overweight (25–29.9), or obese (30+). It is a population-screening tool and does not account for muscle mass, bone density, or fat distribution.
Yes. Use the work-hours calculators to total hours, subtract breaks, and estimate overtime and earnings.
No—calculations run in your browser, and inputs are not uploaded.
No. Open any calculator, enter your values, and get your result immediately—no registration required. No email address, password, or personal information is collected to use these tools.
No. All calculations happen entirely in your browser using JavaScript. No personal data—height, weight, age, health metrics, or financial figures—is sent to a server. Inputs are processed locally and discarded when you close the tab.
The Calorie Calculator uses the Mifflin-St Jeor equation to estimate Basal Metabolic Rate (BMR) from age, sex, height, and weight, then multiplies by an activity factor for TDEE, and derives calorie targets for loss, maintenance, or gain.
Profit margin is profit as a percentage of selling price: (selling price − cost) ÷ selling price × 100. Markup is profit as a percentage of cost: (selling price − cost) ÷ cost × 100. The Profit Margin Calculator shows both.
Break-even units = fixed costs ÷ (selling price − variable cost per unit). The Break-Even Calculator shows this instantly with revenue and cost context.
Yes. The Freelance Rate Calculator takes your desired annual income, expenses, holiday weeks, and billable hours per week, then computes the minimum hourly rate to reach your goal after costs.
Runs in your browser—no signup, no upload, and inputs are not sent to servers.
Uses standard formulas and returns results with sensible rounding for display.
Financial, medical, and payroll results are estimates. For decisions with real consequences, confirm with official policies and professionals.
More free tools for the same workflow.
Calculate sale price and savings from percent or fixed discounts. Reverse original price too. No upload—runs locally in your browser. Free.
Calculate BMI from height and weight using metric or imperial units. See BMI category ranges and use it as a quick screening estimate.
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Reviewed by EverydayTools Editorial Team on 2026-05-20.