Enter proposed terms
How it is calculated
Monthly rate = annual rate ÷ 12. Number of payments = years × 12. For a positive rate, monthly payment = principal × monthly rate ÷ (1 − (1 + monthly rate)−number of payments). At zero interest, monthly payment = principal ÷ number of payments. Total paid = monthly payment × number of payments.
This is a simplified amortization estimate. It omits taxes, fees, balloon payments, variable rates, payment timing, and legal terms. A payment schedule does not determine fair value or suitability. General education only, not engineering, legal, tax, or investment advice. Get qualified professional review. Licensed PE judgment and local codes govern engineering work.
Example scenario
A hypothetical civil engineering firm owner enters a $120,000 buyout balance, a 0% annual interest rate, and a 5 year amortization term. The calculator reports 60 monthly payments, a $2,000 monthly payment, $120,000 total paid, and $0 interest. These hypothetical terms illustrate a simplified payment schedule, not a negotiated agreement or recommendation. The estimate can help the owner and a potential internal successor discuss whether the payment amount fits an initial cash flow conversation. Before treating it as a workable plan, check the agreed balance, payment timing, and any fees, tax effects, security, or other terms. The calculator omits balloon payments and variable terms, among other details. Have qualified legal, tax, and financial professionals review a proposed arrangement before the parties rely on it.
Method, inputs and limits
Purpose
Estimate level monthly payments and total interest for a financed buyout balance using monthly amortization.
Inputs and defaults
Buyout balance: $500,000; annual interest rate: 6%; amortization term: 10 years. Balance and rate are nonnegative; term is above zero.
Formulas
Number of payments = years × 12. Monthly rate = annual rate ÷ 100 ÷ 12. For positive rate, payment = principal × rate ÷ (1 − (1 + rate)^−n). At zero rate, payment = principal ÷ n. Total paid = payment × n. Total interest = total paid − principal.
Outputs
Number of monthly payments, monthly payment, total paid, total interest.
Test cases, expected values
- Defaults: 120 payments; $5,551.03 monthly; $666,123.01 total paid; $166,123.01 interest (displayed values rounded to cents; calculation uses full precision).
- $120,000 balance, 0% rate, 5 years: 60 payments; $2,000 monthly; $120,000 total; $0 interest.
- $24,000 balance, 12% rate, 2 years: 24 payments; $1,129.76 monthly; $27,114.32 total; $3,114.32 interest (displayed values rounded to cents; calculation uses full precision).
Disclaimer
Simplified amortization estimate, not a negotiated or legally binding schedule. Omits taxes, fees, balloon payments, variable terms, and payment timing. Get qualified legal, tax, and financial review. General education only. Licensed PE judgment and local codes govern engineering work.
