Tip · BMI · Converter · Percent
Four calculators in one — tip, BMI, converter & percent. 100% free, no sign-up, runs offline on your device.
A tip calculator finds the gratuity and the per-person share of a restaurant bill. The formula is tip = bill × (tip% ÷ 100), then total = bill + tip, and each person = total ÷ people. In the US, 15–20% is customary for table service; 18% is a common default. Example: a $60 bill at 20% is a $12 tip, $72 total, $36 each between two people.
Body Mass Index estimates whether your weight is healthy for your height. Metric: BMI = kg ÷ m². Imperial: BMI = 703 × lb ÷ in². The WHO ranges are: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese. BMI is a screening indicator only and does not measure body fat or muscle mass.
Convert length, weight, volume and temperature instantly. Common factors: 1 mile = 1.609 km, 1 kg = 2.205 lb, 1 US gallon = 3.785 L. Temperature uses °F = °C × 9/5 + 32 and K = °C + 273.15. Every conversion is computed on-device, so results are exact and work offline.
Three everyday percentage jobs in one place. X% of Y = Y × X ÷ 100 (e.g. 15% of 200 = 30). X is what % of Y = X ÷ Y × 100 (e.g. 30 of 120 = 25%). Percent change = (new − old) ÷ old × 100 (e.g. 50 to 65 is a +30% increase).
Built and maintained by KunStudio · Last updated 10 July 2026
Multiply the bill by the tip percentage divided by 100 to get the tip, add it to the bill for the total, then divide by the number of people. Example: a $48.50 bill at 18% is $8.73 tip, $57.23 total, $28.62 each between two people.
BMI = weight in kilograms ÷ height in metres squared (kg/m²). Under 18.5 is underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese. It is a general screening tool and does not account for muscle mass.
To find X% of Y, multiply Y by X and divide by 100. Example: 15% of 200 = 200 × 15 ÷ 100 = 30. To find what percent X is of Y, divide X by Y and multiply by 100.
Yes — completely free, no sign-up. Every calculation runs in your browser on-device, so it works offline after the first load and never sends your inputs to a server.
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