Splitting the bill without the awkward math at the table
Pick the tip percentage first, then divide — doing it in the other order is how arguments start. The Tip Calculator spits out the tip, the total, and each person's share in one step, so nobody's doing long division on a napkin.
If people ordered wildly different amounts, a flat split feels unfair fast. The Bill Split Calculator handles an uneven group, and I'd add tax and tip proportionally rather than splitting them evenly. On that note, check the Sales Tax Calculator too — in states where menu prices don't include tax, tipping on the post-tax total nudges the bill up more than people expect.
Big pack, small pack: which one's actually cheaper
Bigger isn't automatically better value. Supermarkets count on shoppers assuming it is, and pricing the mid-size box on sale is a pretty common trick. Run the numbers through the Unit Price Calculator and it converts every option to price per gram, litre, or item — that's the only comparison that's actually fair when the containers don't match.
Running costs work the same way. Plug an appliance's wattage and hours of use into the Electricity Cost Calculator and you'll often find some small gadget that's always plugged in costs more over a year than the thing you only run occasionally at high power. Worth pairing with the Sales Tax Calculator too, if you're comparing quoted prices across state lines.
Budgeting a trip or a task before you commit to it
Driving costs come down to two numbers: consumption and price. Start with the Fuel Economy Calculator — your real MPG from a tank and an odometer reading, which nearly always lands below the sticker figure. Then feed that into the Gas Cost Calculator for the actual trip distance and current fuel price.
Time deserves the same treatment. Before opening a long document, the Reading Time Calculator tells you roughly how long it'll take. And before starting a big file transfer, run it through the Download Time Calculator — one thing that trips people up constantly is that megabits and megabytes aren't the same unit, they're off by a factor of eight.
Frequently asked questions
- How much should I tip?
- 18-20% is the norm for US table service, 15% if service was just okay, more if it was genuinely great. Counter service and delivery follow their own local rules, and once you leave the US and parts of Canada, tipping drops off quickly — it's minimal or nonexistent across much of Europe and Asia.
- How do I compare prices between different package sizes?
- Divide price by quantity — per 100g, per litre, per item — and compare those numbers instead of the sticker price. Shelf tags sometimes do this for you already, but watch out: different brands on the same shelf often use different units, which makes eyeballing it useless.
- How much does it cost to run an appliance?
- Wattage times hours used, divided by 1,000 for kilowatt-hours, times your rate per kWh. Example: a 1,500W heater running 5 hours at $0.15/kWh comes out to about $1.13.
- How do I calculate my car's real fuel economy?
- Fill the tank all the way, zero the trip meter, drive as you normally would, then refill and divide miles driven by gallons it took to fill back up. One tank gives you a data point; a few tanks averaged together gives you something reliable.
- Why is my download slower than my internet speed suggests?
- Providers advertise speed in megabits per second, but file sizes are measured in megabytes — and there are eight bits in a byte. So a 100 Mbps connection tops out around 12.5 MB per second, before you even factor in server limits, network overhead, or other devices sharing the same connection.