How do u find interest rate

A = P (1 + rt)

A = Total Accrued Amount (principal + interest) P = Principal AmountI = Interest Amountr = Rate of Interest per year in decimal; r = R/100R = Rate of Interest per year as a percent; R = r * 100t = Time Period involved in months or years

From the base formula, A = P (1 + rt) derived from A = P + I and I = Prt so A = P + I = P + Prt = P (1 + rt)

Note that rate r and time t should be in the same time units such as months or years. An example would be ...

A = P (1 + rt)

A = Total Accrued Amount (principal + interest)

P = Principal Amount

I = Interest Amount

r = Rate of Interest per year in decimal; r = R/100

R = Rate of Interest per year as a percent; R = r * 100

t = Time Period involved in months or years

From the base formula, A = P (1 + rt) derived from A = P + I and I = Prt so A = P + I = P + Prt = P (1 + rt)