Free Lifestyle Calculators
Split a bill, estimate fuel and electricity costs, convert your pet's age, or work out your GPA - handy free lifestyle calculators.
About Lifestyle Tools
Work out gratuity and split the bill with the Tip Calculator, budget a journey with the Fuel Cost Calculator, see what an appliance costs to run with the Electricity Bill Calculator, convert your dog or cat's age with the Pet Age Calculator, or track your grades with the GPA Calculator.
These everyday helpers turn small, fiddly calculations into instant answers - all free and private in your browser.
Small calculations, repeated often
The tools in this group cover decisions that individually cost little and collectively add up: what to tip, what a journey costs in fuel, what an appliance adds to the electricity bill, how to convert a grade average. None is complicated, and each has a specific trap worth knowing about.
The traps
- Tipping norms vary enormously and reflect how staff are paid rather than generosity. 18–22% is expected in the United States, 10–12.5% in the UK, and nothing at all in Japan, South Korea or China, where a tip can cause genuine discomfort. Check whether a service charge is already on the bill before calculating.
- Fuel economy figures are not comparable across systems: an imperial gallon is about 4.55 litres and a US gallon 3.79, so a car rated 40 mpg in the UK is roughly 33 mpg by US measurement for identical real efficiency. Official manufacturer figures are typically 10–25% optimistic against real driving.
- Electricity bills are usually tiered, so the marginal cost of the last units is much higher than the average. Cutting consumption 10% can cut the bill by considerably more if it crosses a threshold. Heating and cooling dominate consumption; lighting, which people focus on, rarely does.
- GPA scales differ between institutions and countries, and conversions between percentage systems and GPA are approximate rather than exact. Use your own institution's published grade table.
Where the real savings are
For fuel, speed and an unused roof rack matter far more than driving style — aerodynamic drag rises with the square of speed, and an empty roof box costs 10–25% at motorway speed. For electricity, one degree on a heating or cooling setpoint typically changes consumption by 5–10%, which is the single largest controllable lever in most homes.
Frequently Asked Questions
Can the tip calculator split a bill?
Yes. It works out the tip and divides the total evenly among any number of people.
Is one dog year really seven human years?
No, that is a myth. The Pet Age Calculator uses more accurate, size-aware formulas.
Are these lifestyle tools free?
Yes, all of them are free with no sign-up.
How much should I tip?
It depends entirely on the country, because the norm reflects how staff are paid. 18–22% is expected in the United States and 10–12.5% in the UK, while tipping is not customary at all in Japan, South Korea or China.
Why is my fuel economy worse than the official figure?
Manufacturer figures come from standardised laboratory cycles with gentle acceleration and no auxiliary loads. Real driving is typically 10–25% worse. Measure your own over a few full tanks.
Why did my electricity bill rise more than my usage?
Most likely tiered pricing, where the rate increases once monthly consumption crosses a threshold. The extra units are billed above your average rate, so the bill rises faster than consumption does.