Exterior Door ROI Calculator

Steps to get a realistic estimate

1. Enter your door, installation, and any permit or miscellaneous costs.
2. Add rebates or credits to reduce your net upfront investment.
3. Estimate year‑one savings from energy, maintenance, and insurance changes.
4. Choose a resale lift method and provide either percent or amount.
5. Open advanced assumptions to set holding period and discount rate.
6. If you plan to finance, enable it and enter loan terms.
7. Press Calculate ROI to see results above the form.

Core finance logic behind the results

• Net upfront cost = Door + Installation + Misc + Loan fees − Rebates.
• Annual savings grow each year: Savings_y = Savings₁ × (1 + g)^y−1.
• Resale benefit (net) = Value lift × (1 − selling cost rate).
• ROI = (Total benefits − Total out‑of‑pocket cost) ÷ Total out‑of‑pocket cost.
• NPV = Σ CashFlow_t ÷ (1 + r)^t, using your discount rate r.
• Payback is the first year cumulative cash flow becomes non‑negative.
• IRR is the rate where NPV equals zero (if it exists).

Sample scenarios for quick comparison

Cost drivers and typical ranges

Exterior door projects usually combine material, installation, and small extras. A mid‑range insulated door may run $1,200–$2,500, while installation often adds $400–$1,200 depending on framing, sidelights, and lock upgrades. Permits, disposal, paint, and weatherstripping can add $50–$250. Use rebates or utility credits to reduce the net upfront outlay shown in the summary.

Annual savings and sensitivity

Savings are commonly dominated by air‑sealing and reduced maintenance. If improved sealing cuts heating and cooling losses, year‑one energy savings might be $50–$200, then grow with energy prices using the savings growth rate. Maintenance savings may be $20–$80 by avoiding rot repair, repainting, and hardware replacement. Insurance savings, when available, are usually modest at $0–$60 per year, but still cumulative helpful. Run a low and high scenario to see how payback shifts.

Resale value lift and selling friction

A modern, secure entry can influence curb appeal and buyer perception. This calculator lets you model resale lift as a percent of home value or as a fixed amount, then subtract selling costs such as commissions. For example, a $1,500 value lift with a 6% selling cost rate yields a $1,410 net resale benefit. If you expect to sell sooner, resale assumptions matter more.

Discount rate, NPV, and decision thresholds

ROI alone can hide timing. NPV discounts future net cash flows using your chosen discount rate, reflecting opportunity cost and risk. A higher discount rate reduces the present value of long‑term savings, making quick payback projects more attractive. If NPV is positive, the upgrade clears your hurdle rate; if NPV is negative, savings or resale lift must improve.

Financing and holding‑period strategy

When financing is enabled, the schedule includes loan payments and any remaining balance at sale. A longer loan term lowers monthly payments but can reduce early‑year net cash flow. If your holding period is shorter than the loan term, the remaining balance can offset resale benefits. Consider matching the loan term to your expected holding period to avoid surprises.

What does ROI represent in this calculator?

ROI compares total benefits from savings and resale lift against total out‑of‑pocket costs over your holding period. It is expressed as a percent and does not discount future cash flows.

Why can NPV be positive when ROI looks modest?

NPV accounts for timing. If most benefits arrive early, discounting has less impact and NPV can stay positive even with moderate total returns. If benefits arrive late, NPV may fall quickly.

How should I estimate resale value increase?

Use a conservative value lift based on comparable listings and buyer preferences in your area. If unsure, test a range such as $500–$2,000 or 0.2%–1.0% of home value, then compare outcomes.

What discount rate should I use?

Choose a rate that reflects your opportunity cost and risk. Many homeowners test 4%–10%. Higher rates favor quick payback projects; lower rates place more weight on long‑term energy savings.

How does financing change the results?

Financing spreads upfront costs into payments, which can reduce early net cash flow. The calculator also subtracts any remaining balance at sale. If you sell before the loan ends, the payoff can materially reduce ROI.

Why does payback show “Not reached”?

Payback is the first year cumulative cash flow turns non‑negative. If savings and resale lift never recover the initial investment within your holding period, payback is not reached. Extend years or adjust assumptions to test.