Loans - Exam FM formula sheet

Every Exam FM formula in loans on one printable sheet, condensed from the 3 reference pages that teach them.

3 topics, 12 formula lines. Every line is condensed from the Exam FM formula pages, which stay free to read in full. Print this page to get the sheet on paper; the site chrome drops away.

What is on this sheet

Loans

Amortisation

Level payment
P=Lan‾∣iP = \dfrac{L}{a_{\overline{n}|i}}
Interest in payment t
It=P(1−v n−t+1)I_t = P\left(1 - v^{\,n-t+1}\right)
Principal in payment t
Pt=P v n−t+1P_t = P\,v^{\,n-t+1}
Principal repayments grow
Pt+1=Pt(1+i)P_{t+1} = P_t(1+i)
Totals
∑t=1nPt=L,∑t=1nIt=nP−L\sum_{t=1}^{n} P_t = L, \qquad \sum_{t=1}^{n} I_t = nP - L

Outstanding balance

Prospective
Bt=P an−t‾∣iB_t = P\,a_{\overline{n-t}|i}
Retrospective
Bt=L(1+i)t−P st‾∣iB_t = L(1+i)^{t} - P\,s_{\overline{t}|i}
Recursion
Bt=Bt−1(1+i)−PB_t = B_{t-1}(1+i) - P

Sinking funds

Sinking fund deposit
D=Lsn‾∣jD = \dfrac{L}{s_{\overline{n}|j}}j is the rate the fund earns
Total outlay
Total=Li+D\text{Total} = Li + D
Equivalent amortisation
Li+Lsn‾∣j=Lan‾∣i  ⟺  i=jLi + \dfrac{L}{s_{\overline{n}|j}} = \dfrac{L}{a_{\overline{n}|i}} \iff i = j
Net amount owed
L−D st‾∣jL - D\,s_{\overline{t}|j}