Understand every
number.
Convert a measurement. Compare a loan. Learn the formula. Practical answers you can put to work, with the calculation right beside them.
Find your answerLiters per 100 km
or kilometers per liter?
Choose the right unit and your fuel estimate starts making sense.
Understand fuel economyWhat are you working on?
Explore the library
L/100 km vs km/L: understand your fuel economy
Learn which fuel economy number to enter, convert L/100 km to km/L, and calculate liters needed for a trip with a worked 150 km example.
guideUS vs Imperial gallons: why your fuel result changes
Understand US and Imperial gallon sizes, the difference between US and UK mpg, and how to match fuel prices to the right gallon.
guideHow monthly loan payments are calculated
See the fixed-rate loan payment formula, a zero-interest example, and the difference between principal, interest and the full monthly bill.
guideShorter vs longer loan terms: compare the full cost
Compare monthly payments and total interest for different loan lengths, with editable comparison tools and clear assumptions.
guideProfit margin vs markup: choose the right percentage
Calculate margin and markup from cost and selling price, and see why a 25% markup does not create a 25% profit margin.
guideSimple vs compound interest: a worked comparison
Understand how interest on interest changes a balance, compare simple and annual compound growth, and check contribution timing.
guideHow to calculate two successive discounts
Calculate stacked discounts correctly and understand why 20% off followed by 10% off is a total discount of 28%, not 30%.
guideCups to grams: why the ingredient matters
Learn why cups cannot convert directly to grams without density, distinguish US and metric cups, and calculate a sample ingredient mass.
guideSI prefixes and scientific notation explained
Read all 24 SI prefixes, distinguish uppercase and lowercase symbols, and convert decimal powers without confusing a measurement with its unit.
comparison15-year vs 30-year loan comparison
Compare 15-year and 30-year fixed-rate loans with editable principal and separate rates. See monthly payments, total repayment and interest side by side.
comparison10-year vs 20-year loan comparison
Compare 10-year and 20-year fixed-rate loans with editable principal and separate rates. See monthly payments, total repayment and interest side by side.
comparison20-year vs 30-year loan comparison
Compare 20-year and 30-year fixed-rate loans with editable principal and separate rates. See monthly payments, total repayment and interest side by side.
conversionMillimeters to centimeters converter
Convert millimeters to centimeters with an editable calculator, worked example, formula and reference table. Check the unit definitions before you convert.
conversionMillimeters to meters converter
Convert millimeters to meters with an editable calculator, worked example, formula and reference table. Check the unit definitions before you convert.
conversionMillimeters to kilometers converter
Convert millimeters to kilometers with an editable calculator, worked example, formula and reference table. Check the unit definitions before you convert.
conversionMillimeters to inches converter
Convert millimeters to inches with an editable calculator, worked example, formula and reference table. Check the unit definitions before you convert.
conversionMillimeters to feet converter
Convert millimeters to feet with an editable calculator, worked example, formula and reference table. Check the unit definitions before you convert.
conversionMillimeters to yards converter
Convert millimeters to yards with an editable calculator, worked example, formula and reference table. Check the unit definitions before you convert.