SOLVE FOR
AMOUNT
A = P(1+r/m)^(m·t)
ROUNDING
2DP
Money usually 2dp
PRINCIPAL (£)
P
Starting amount
FINAL AMOUNT (£)
A
Needed to solve P/r/t
RATE (%)
r
Annual percentage rate
TIME (YEARS)
t
Years (can be decimals)
COMPOUNDING
12/YR
m = times per year
INTEREST (£)
I
I = A − P
WORKING
—
—
—
—
—
FINAL AMOUNT
READY
—
PAGE 1/2
SOLVE FOR
AMOUNT
A = P(1+r/m)^(m·t)
ROUNDING
2DP
Money usually 2dp
PRINCIPAL (£)
P
Starting amount
FINAL AMOUNT (£)
A
Needed to solve P/r/t
RATE (%)
r
Annual percentage rate
TIME (YEARS)
t
Years (can be decimals)
COMPOUNDING
12/YR
m = times per year
INTEREST (£)
I
I = A − P
WORKING
—
—
—
—
—
FINAL AMOUNT
READY
—
PAGE 1/2
MAIN FORMULA
A = P(1 + r/m)^(m·t)
r is decimal: 6% → 0.06
m is times per year
HOW TO USE
1) Choose SOLVE FOR
2) Enter known values
3) Set COMPOUNDING
4) Press SOLVE
INTEREST
I = A − P
Compute A first, then subtract
Money answers → 2dp
REARRANGE
P = A ÷ (1+r/m)^(m·t)
t = ln(A/P) ÷ (m·ln(1+r/m))
Rate uses roots (see formula)
WORKED EXAMPLE
P=£500, r=6%, t=3
m=12 (monthly)
A=500(1+0.06/12)^36
A ≈ £598.32
TIP
If m=1 it’s annual compounding
Higher m → slightly more growth
Use sensible inputs (no negatives)
PAGE 2/2