Money & Finance
Budgeting, borrowing, interest and pay — the arithmetic behind the decisions that cost the most.
A rate quote leads with principal and interest, but the number that actually leaves your account every month has two more pieces bolted on. Here's the formula, a real example, and what a smaller down payment costs you.
A fixed $150 a month sounds like progress until you run it against a 22% APR. Here's the payoff math, a real example, and why doubling the payment does more than double the speed.
Comparing a $32/hour contract to a $72,000 salaried offer isn't obvious until both are in the same units. Here's the formula both directions, and the “weeks per year” trap that quietly favors one offer over the other.
Fifty percent needs, thirty percent wants, twenty percent savings: the ratio is famous, but most people never actually do the division. Here's the math on real take-home pay, including what to do when “needs” won't fit in 50%.
Your first mortgage payments are mostly interest, and that isn't a bank trick — it's arithmetic. Here's the formula, a real worked example, and the one move that actually shortens a loan.
One division tells you how long money takes to double. Here's why it works — and the big lesson about rates hiding inside it.
Your interest earns interest. That one twist is why a ten-year head start can out-run thirty years of saving that began late.
What makes a mileage claim stand up is not the total. It is that the log was kept at the time and says why.
Some programs taper as income rises. Others stop dead at a line. Here is the arithmetic of the second kind, worked all the way through.
Premium, subsidy and out-of-pocket exposure are three numbers. Change how much care a year needs and the cheapest plan can flip.
Monthly payment and total paid are two different questions. Lowering the first almost always raises the second.
One income, several programs, and none of them count it the same way. How to work out your own picture instead of assuming it.