The rate is often given per annum which means per year. Determine the total amount borrowed. How to Calculate a Simple Interest Payment.
Simple Interest Formulas and Calculations.
Check with your calculator. Simple Interest Simple interest is money earned on the original amount of your deposit. Calculating Interest When the Time Is Given in Days. Calculate Total Amount Accrued Principal Interest solve for A A P 1 rt Calculate Principal Amount solve for P P A 1 rt Calculate rate of interest in decimal solve for r r 1t AP - 1 Calculate rate of interest in percent R r.