Everyday Calculators — Discount, Tip, Fuel Cost & BMI
4 everyday calculators in one: work out discounts and sales tax, split a restaurant bill with tip, estimate fuel cost for a trip, and calculate your BMI with a healthy weight range.
- Pick a mode from the pill bar: Discount & Sales Tax, Tip & Bill Split, Fuel Cost, or BMI Calculator.
- Discount & Sales Tax: enter the original price, a percentage or flat discount, and a tax rate — choose whether tax applies before or after the discount.
- Tip & Bill Split: enter the bill amount, pick a quick tip percentage (or enter a custom one), and the number of people to split with.
- Fuel Cost: enter trip distance, vehicle efficiency, and fuel price (with km/mi and L per 100km/MPG toggles) to see total fuel needed and cost.
All processing happens entirely in your browser. Your data never leaves your device.
Key Features
- Discount calculator supporting both percentage and flat-amount discounts
- Toggle to apply sales tax before or after the discount, with a full breakdown
- Tip calculator with quick-select buttons (10/15/18/20/25%) plus a custom tip field
- Bill splitter that divides the tip and total evenly across any number of people
- Fuel cost calculator with km/mi and L-per-100km/MPG unit toggles and a round-trip option
- BMI calculator with cm or ft+in height and kg or lb weight input
- Color-coded WHO BMI category badge (Underweight, Normal, Overweight, Obese)
- Healthy weight range shown for your exact height — 100% client-side, no data leaves your device
About Everyday Calculators
Small everyday math — figuring out a final sale price, splitting a dinner bill fairly, budgeting for a road trip's fuel, or checking a quick health metric — usually means reaching for four different single-purpose calculators. ForgeKit's Everyday Calculators bundles the most commonly needed ones into a single tool with a clean, consistent interface.
The Discount & Sales Tax calculator handles the two most common real-world orderings: tax calculated on the discounted price (typical at retail checkouts) or tax calculated on the original price with the discount applied afterward. The Tip & Bill Split calculator offers one-tap buttons for common tip percentages plus a custom field, and instantly divides the total across any number of people. The Fuel Cost calculator supports both metric (L/100km) and imperial (MPG) efficiency units alongside km/mi distance, with a round-trip toggle for planning longer journeys.
The BMI Calculator computes Body Mass Index using the standard kg/m² formula, supports both metric and imperial height/weight units, and shows your result against the World Health Organization's official weight categories along with the healthy weight range for your specific height. Every calculation happens instantly in your browser as you type — nothing is uploaded or stored.
Frequently Asked Questions
"After discount" calculates tax on the price once the discount has already been subtracted — the way most retail checkouts work. "Before discount" calculates tax on the full original price first, then subtracts the discount afterward. The two orderings can produce slightly different final totals, so the tool shows both breakdowns clearly.
The calculator converts your chosen efficiency unit internally so the math is consistent — MPG (US gallons) is converted to L/100km using the standard 235.214 conversion constant, distance is converted between km and miles as needed, and the fuel price field automatically matches whichever volume unit (liters or gallons) your efficiency selection implies.
BMI is a simple screening tool based only on height and weight — it doesn't account for muscle mass, bone density, age, sex, or body composition. Athletes and very muscular individuals, for example, can show a high BMI while being perfectly healthy. Use it as a general guide, not a diagnosis.
The Tip & Bill Split mode divides the total evenly across the number of people you enter. For uneven splits (e.g. someone ordered a more expensive item), you'd calculate each person's share manually using the tip percentage and per-item costs.
No. All four calculators run entirely as client-side JavaScript in your browser. No prices, distances, or health data are transmitted or stored anywhere.