Tip Calculator
Calculate the perfect tip for any bill. Split it among friends instantly.
How to calculate a tip: Multiply your bill by the tip percentage (e.g., 18% = 0.18). Add that amount to your bill for the total. When splitting, divide the total by the number of people. Common tip amounts in the US: 15% for adequate service, 18–20% for good service, 25%+ for exceptional service.
BMI Calculator
Check your Body Mass Index. Works for both metric and imperial units.
What is BMI? Body Mass Index (BMI) is a screening tool that estimates body fat based on height and weight. While it doesn't measure body fat directly, it correlates with health risks. BMI = weight (kg) ÷ height² (m²). For women, note that healthy BMI ranges may vary slightly due to naturally higher body fat percentages.
Loan / Amortization Calculator
See your monthly payment, total interest, and full amortization schedule.
How amortization works: Each monthly payment has two parts — principal (reduces your balance) and interest (lender's fee). Early in the loan, most of your payment goes to interest. Over time, more goes to principal. Use this calculator to compare loan terms and see how extra payments can save thousands in interest.
Hours Calculator for Work
Track your work hours easily. Accounts for break time and calculates overtime.
Why track hours? Accurate time tracking ensures fair pay, helps with overtime calculations, and keeps records for compliance. Most US states require overtime pay (1.5× rate) for hours worked beyond 40 per week or 8 per day. This calculator handles shifts that cross midnight and custom break deductions.
Calorie Calculator (TDEE)
Estimate your Total Daily Energy Expenditure based on age, sex, and activity level.
What is TDEE? Total Daily Energy Expenditure is the number of calories you burn per day. It's calculated from your Basal Metabolic Rate (BMR) × activity level. To lose weight, eat 500 calories below your TDEE. To gain weight, eat 500 above. This calculator uses the Mifflin-St Jeor equation, the most accurate formula for most people.
Percentage Calculator
Solve any percentage problem: what is X% of Y, X is what % of Y, and more.
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Common percentage formulas: "X% of Y" = Y × (X/100). "X is what % of Y" = (X/Y) × 100. "Increase X by Y%" = X × (1 + Y/100). "Decrease X by Y%" = X × (1 − Y/100). Percentages are used daily for discounts, tips, tax, interest rates, and grade calculations.
Age Calculator
Calculate your exact age in years, months, and days. Also shows next birthday countdown.
How age is calculated: Your exact age is the time elapsed from your date of birth to today. This calculator accounts for leap years and varying month lengths. It also shows your next birthday countdown — useful for planning celebrations or calculating age for legal purposes (driving, voting, retirement).
Discount Calculator
Find out how much you save and the final price after a discount.
How to calculate a discount: Discount amount = original price × (discount % / 100). Final price = original price − discount amount. For example, 20% off $100 = $20 discount, $80 final price. Use this calculator for Black Friday deals, coupon codes, and clearance sales.
Pregnancy Calculator
Track your pregnancy. Enter your LMP (last menstrual period) to see current week, due date, and trimester.
How pregnancy weeks are counted: Pregnancy is counted from the first day of your last menstrual period (LMP), which is about 2 weeks before conception. A full-term pregnancy is 40 weeks (280 days) from LMP, or 38 weeks from conception. Trimesters: 1st (weeks 1–13), 2nd (weeks 14–27), 3rd (weeks 28–40).
Gas / Fuel Calculator
Calculate your fuel cost for a trip. Enter distance, MPG, and gas price.
How to calculate fuel cost: Fuel cost = (distance ÷ MPG) × gas price per gallon. For example, 300 miles at 25 MPG uses 12 gallons. At $3.50/gallon, the trip costs $42. Use this calculator to budget road trips, compare the cost of different vehicles, and decide whether to fly or drive.