This automotive finance calculator estimates monthly car lease payments by breaking down vehicle depreciation, rent charges (finance interest), and sales tax. When shopping for a new vehicle at a dealership, understanding how money factors and residual percentages influence payments helps consumers negotiate better terms.

### Lease Payment Mathematical Formulas The calculator computes three separate payment components in client memory:

- **Residual Value ($V_{\text{res}}$):** $V_{\text{res}} = \text{MSRP} \times (\text{residualPercent} / 100)$. - **Net Capitalized Cost ($C_{\text{net}}$):** $C_{\text{net}} = \text{negotiatedPrice} - \text{downPayment}$. - **Monthly Depreciation ($D_{\text{mo}}$):** $D_{\text{mo}} = (C_{\text{net}} - V_{\text{res}}) / \text{termMonths}$. - **Monthly Rent Charge ($R_{\text{mo}}$):** $R_{\text{mo}} = (C_{\text{net}} + V_{\text{res}}) \times \text{moneyFactor}$. - **Pre-Tax Monthly Payment:** $P_{\text{pre}} = D_{\text{mo}} + R_{\text{mo}}$. - **Monthly Sales Tax:** $T_{\text{mo}} = P_{\text{pre}} \times (\text{salesTaxRate} / 100)$. - **Total Monthly Payment:** $P_{\text{total}} = P_{\text{pre}} + T_{\text{mo}}$. - **Equivalent Annual Percentage Rate (APR):** $\text{APR} = \text{moneyFactor} \times 2,400$.

### Worked Numeric Example Suppose a car buyer reviews a 36-month lease offer on a crossover vehicle: - **Vehicle MSRP:** $42,000 - **Negotiated Selling Price:** $39,000 - **Residual Value Percentage:** 58% - **Lease Term:** 36 months - **Money Factor:** 0.0022 - **Down Payment (Cap Reduction):** $2,500 - **Sales Tax Rate:** 7.0%

**Step-by-Step Breakdown:** 1. **Residual Value:** $42,000 \times 0.58 = \$24,360$. 2. **Net Cap Cost:** $39,000 - 2,500 = \$36,500$. 3. **Monthly Depreciation:** $(36,500 - 24,360) / 36 = 12,140 / 36 \approx \$337.22$. 4. **Monthly Rent Charge:** $(36,500 + 24,360) \times 0.0022 = 60,860 \times 0.0022 \approx \$133.89$. 5. **Pre-Tax Monthly:** $337.22 + 133.89 = \$471.11$. 6. **Monthly Sales Tax:** $471.11 \times 0.07 \approx \$32.98$. 7. **Total Monthly Payment:** $471.11 + 32.98 \approx \$504.09$ (rounds to **$504/mo**). 8. **Equivalent APR:** $0.0022 \times 2,400 = 5.28\%$.

### Client-Side Processing Note All calculations run in client-side JavaScript. No vehicle prices, personal finance details, or credit scores are transmitted across any network.