Amortization

Measured as

Measure Amortization with the same date, unit basis, and accounting or policy definitions used in the rest of your model.

Misused when

• Assuming the interest share is constant over the term.
• Comparing loans without aligning term length and compounding.
• Ignoring fees that change the effective rate.
• Using amortization schedules with mismatched payment frequency.
• Confusing accounting amortization with loan amortization.

Operator takeaway

• Early payments are mostly interest; principal share grows over time.
• An amortization schedule shows the split between interest and principal each period.
• Longer terms lower monthly payments but increase total interest paid.
• Tie Amortization to the same balance-sheet date, scenario, and decision memo you are using elsewhere in the model.
• Document which claims, costs, or adjustments your team includes before comparing numbers across forecasts, covenants, or valuation work.

Next decision

• Quantify the impact with Loan Payment Calculator if you need to turn the definition into an operating assumption.
• Read Loan amortization: how monthly payments and total interest work if the decision depends on interpretation, policy, or trade-offs beyond the raw formula.