Finance

Time value of money, loans, cash flows, interest and depreciation.

• Time value of money: the five money keysHow N, I/Y, PV, PMT and FV fit together, and the rule about positive and negative amounts.
• Calculate a monthly loan paymentFind the monthly payment on a loan or mortgage from the amount, rate and length.
• See how much of a payment is interestSplit a run of loan payments into interest, principal and remaining balance.
• How much will my savings grow to?Find the future value of regular deposits that earn interest.
• Find how much to invest todayWork out the amount you need now to reach a target sum in the future.
• Find the interest rateWork out the yearly rate needed to turn one amount into another.
• Find how many payments are neededWork out how long it takes to pay off a loan, or reach a savings goal.
• Net present value of cash flowsAdd up uneven cash flows after discounting each back to today.
• Internal rate of returnFind the yearly return that makes a set of cash flows break even in present value.
• Simple interestInterest on a fixed amount that does not itself earn interest: I = P × r × t.
• Compound interestGrowth where interest is added to the balance and then earns interest itself.
• Percent change between two numbersFind how much a value rose or fell, as a percentage of where it started.
• Depreciation of an assetSpread the cost of an asset over its useful life with the straight-line method.
• Price of a bondFind what a bond is worth today, given its coupon and the yield you want.
• Days between two datesCount the days from one date to another, and handle leap years for you.
• Convert a nominal rate to an effective rateFind the real yearly rate when interest is added more than once a year.
• Break-even pointHow many units must you sell before income covers your costs?
• Profit margin and markupFind margin as a share of the selling price, from cost and price.