Methodology
Every rate, multiplier and formula our calculators use is published on this page. If you think a number is wrong, you can see exactly which one and tell us.
Last reviewed
Principles
- Ranges, not point estimates. Any honest construction or insurance estimate is a range. A single number implies a precision that does not exist before someone has stood on your roof.
- Line items, not lump sums. Showing the components is what lets you compare our figure to a real quote and find what a contractor left out.
- Conservative assumptions. Where a choice exists we take the less flattering one — a 0.80 solar derate rather than 0.85, 3% rate escalation rather than 5%.
- No hidden lead generation. Inputs are processed entirely in your browser with JavaScript. Nothing is transmitted to us or to anyone else. There is no quote form because we do not sell your details.
- We say when we do not know. Where law or incentive rules are in flux — the federal solar tax credit being the clearest current case — we default to zero and tell you to verify, rather than quoting a figure that may be obsolete.
Where the numbers come from
Rates are assembled from published contractor pricing guides, manufacturer and supplier list pricing, published insurance industry rating factors, and publicly available cost surveys, then cross-checked against ranges quoted by regional trade sources. They are calibrated to 2026 US pricing and reviewed periodically. They are not proprietary bid data and they are not a substitute for a local quote.
What these calculators are not
They are planning tools. They are not bids, quotes, appraisals, claim valuations, offers of insurance, or tax, legal or financial advice. Actual prices depend on the specific condition of your property, local code, market conditions and who you hire. Always obtain written quotes from licensed local professionals.
1. Roof Replacement Cost Calculator
Estimating sequence:
- Roof surface = footprint × pitch multiplier.
- Squares = surface ÷ 100. Material is ordered at squares × 1.10 to cover waste at hips, valleys and rakes.
- Material and labor rates applied per square by material type.
- Labor multiplied by pitch difficulty × stories × regional factor.
- Tear-off applied per square, per existing layer, × regional factor.
- Accessories (underlayment, ice-and-water, drip edge, starter, ridge cap, flashing, ventilation) at $70–$120 per square.
- Optional decking, gutters, chimney and skylight reflashing, then permit.
Pitch multipliers
| Pitch | Area multiplier | Labor multiplier |
|---|---|---|
| Low, 2:12–4:12 | 1.06 | 0.96 |
| Moderate, 5:12–7:12 | 1.15 | 1.00 |
| Steep, 8:12–10:12 | 1.28 | 1.18 |
| Very steep, 11:12+ | 1.44 | 1.38 |
Material and labor, per square
| Material | Material $ | Labor $ |
|---|---|---|
| 3-tab asphalt | 115–185 | 165–260 |
| Architectural asphalt | 150–250 | 175–275 |
| Premium designer shingle | 220–390 | 200–300 |
| Corrugated metal | 270–490 | 260–400 |
| Standing seam metal | 520–980 | 420–680 |
| Concrete tile | 390–660 | 340–580 |
| Clay tile | 640–1,180 | 450–780 |
| Synthetic slate | 410–720 | 320–520 |
| Natural slate | 1,020–2,050 | 730–1,450 |
| Cedar shake | 410–720 | 370–620 |
| TPO / EPDM | 260–460 | 210–370 |
Other roof line items
- Stories: 1 = 1.00, 2 = 1.10, 3+ = 1.22
- Tear-off & disposal: $55–$115 per square, per layer
- Accessories: $70–$120 per square
- Decking: 15% of surface assumed replaced, at $2.50–$4.50 per sq ft
- Gutters: perimeter estimated as 4 × √footprint × 1.15, at $8–$16 per linear foot
- Chimney reflash: $350–$1,000. Skylight reflash: $400–$900 each
- Permit & inspection: $250–$800
Regional multipliers (all calculators)
| Region | Factor |
|---|---|
| Northeast (NY, MA, NJ, CT) | 1.22 |
| West Coast (CA, WA, OR) | 1.18 |
| Mountain & Southwest | 1.02 |
| US national average | 1.00 |
| Midwest | 0.98 |
| South Atlantic | 0.93 |
| South Central | 0.88 |
Regional factors are applied to labor, tear-off, disposal and permits — the location-sensitive components. Material prices are treated as broadly national.
2. Homeowners Insurance Calculator
Coverage A is estimated as living area × rebuild cost per square foot by construction quality ($165 builder grade, $195 standard, $245 semi-custom, $330 custom), rounded to the nearest $5,000. It represents rebuild cost, never market value.
Premium is built multiplicatively from a base rate per $1,000 of Coverage A:
| Factor | Values |
|---|---|
| State tier, $ per $1,000 of A | 17.5 extreme · 13.0 very high · 10.5 high · 8.0 average · 6.2 below · 4.6 low · 3.6 lowest |
| Construction | Frame 1.00 · Masonry 0.92 · Superior 0.86 |
| Roof age | 0–5 = 0.88 · 6–10 = 0.96 · 11–15 = 1.08 · 16–20 = 1.24 · 20+ = 1.45 |
| Deductible | $500 = 1.12 · $1,000 = 1.00 · $2,500 = 0.88 · $5,000 = 0.79 · 1% = 0.90 · 2% = 0.81 |
| Claims in 5 years | 0 = 1.00 · 1 = 1.20 · 2+ = 1.48 |
| Insurance score | Excellent 0.82 · Good 1.00 · Fair/poor 1.35 |
| Endorsements | Water backup +$70/yr · Scheduled valuables +$120/yr · Extended replacement +8% |
A ±18% band is applied around the point estimate to reflect carrier-to-carrier variation. The coverage schedule derives B at 10% of A, C at 55%, D at 20%, with liability and medical payments shown at common default limits.
3. Hail Damage Claim Estimator
Replacement cost of the roof uses the installed rates above plus $125–$235 per square for tear-off, disposal, underlayment and flashing, plus permit, × regional factor. Other damaged property is added at typical ranges: gutters and fascia $900–$2,600, window screens $300–$1,100, siding $2,500–$9,000, A/C condenser $400–$2,800.
Depreciation is straight-line: roof age ÷ expected service life, capped at 75%. Expected lives used: 3-tab 18, architectural 27, premium 35, corrugated metal 38, standing seam 55, concrete tile 50, clay tile 75, synthetic slate 45, natural slate 100, cedar 32 years.
Settlement is then: ACV = RCV − depreciation. First payment = ACV − deductible. On a replacement cost policy the withheld depreciation is added back as recoverable once work is completed and invoiced; on an actual cash value policy it is not. The claim maths uses the midpoint of the cost range, because an adjuster settles on a single figure.
The letter generator assembles a template from your inputs entirely in your browser. It is a starting draft, not legal advice.
4. Window Replacement Cost Calculator
Per window: unit cost by style × frame factor × glazing factor × size factor, plus labor by style × installation factor × size × region.
| Factor | Values |
|---|---|
| Frame | Vinyl 1.00 · Aluminium 1.10 · Composite 1.18 · Fiberglass 1.32 · Wood 1.55 · Clad wood 1.70 |
| Glazing | Double low-E 1.00 · +argon 1.08 · Triple 1.30 |
| Size | Standard 1.00 · Large 1.22 · Oversized 1.50 |
| Installation | Insert 1.00 · Full-frame 1.28 |
| Adders, per window | Exterior capping $60–$140 · Interior trim $80–$200 · Lead-safe RRP $60–$150 · Haul-away $25–$60 |
| Adder, per job | Setup & mobilisation $150–$400 |
5. Solar Panel Cost Calculator
Sizing: annual kWh = (monthly bill ÷ rate) × 12. System kW = (annual kWh × offset) ÷ (peak sun hours × 365 × 0.80).
- Derate 0.80 — inverter losses, wiring, soiling, temperature, mismatch.
- Cost per watt — $2.40 value tier, $2.85 standard, $3.40 premium; +$0.20 for a steep or complex roof.
- Adders — electrical panel upgrade $2,500; battery storage $13,500 for 13.5 kWh installed.
- Escalation 3% annually, degradation 0.5% annually, over a 25-year horizon.
- Inverter replacement of $2,200 booked at year 13 on string-inverter systems.
- Exports beyond self-consumption are credited at 40% of retail, reflecting the shift from full retail net metering toward net billing in many states.
- Tax credit defaults to 0%. The federal residential clean energy credit was curtailed by 2025 legislation. Enter a figure only if a tax professional has confirmed your eligibility.
Corrections
If you are a contractor, adjuster, agent or installer and a rate here does not match what you see in your market, we want to know. Tell us the line item, your region, and what you are actually seeing, via the contact page. We publish these numbers precisely so they can be challenged.