Search for a roof replacement cost calculator and most of what comes back is a lead form wearing a calculator costume: it asks for your phone number, then a salesperson calls with the price. This one runs in your browser and sends nothing anywhere. It uses the same installed-cost-per-square ranges as our Greenville roof replacement cost guide, and the same roof-size method as our ZIP cost pages, such as roof cost in 29607.
It is an estimate, and it says so. Tear-off layers, rotted decking, flashing, ventilation and how cut-up the roof is all move a real bid. The written quote a roofer gives you after an inspection is the number that counts; this tells you whether that quote is in a sensible range.
The Calculator
How the Calculator Works
Roofing is priced per square, and one square is 100 square feet of roof surface, not floor space. Most homeowners know their living space, not their roof, so the calculator converts one into the other. If you already have a roofer's measurement in squares, enter it and the calculator skips straight to the price step.
Two stories put the same living space under a smaller roof, so the footprint is your square footage divided by the number of stories. The pitch setting adjusts for how much more surface a steeper roof has over the same footprint; that is plain geometry, shown in the table below. Waste covers the cut-offs at hips, valleys and edges.
| Step | Figure | Basis |
|---|---|---|
| Footprint | Home sq ft ÷ stories | Two stories put the same living space under a smaller roof |
| Roof surface | Footprint × 1.2 × pitch factor | Modelled: one story assumed; a moderate (about 6-in-12) pitch plus overhangs adds about 20% to floor area (the same factor as our ZIP cost pages) |
| Roof squares | Surface × 1.1 ÷ 100 | Modelled: plus 10% cutting waste; one square = 100 sq ft |
| Cost range | Squares × installed cost per square | The per-square ranges on our cost guide, rounded to $100 |
| Pitch setting | Pitch factor | Why |
|---|---|---|
| Low slope (about 4-in-12) | × 0.94 | Roof surface at 4-in-12 compared with 6-in-12, the pitch our base factor assumes |
| Standard (about 6-in-12, most homes) | × 1.00 | The 6-in-12 pitch our base factor already assumes |
| Steep (9-in-12 or more) | × 1.12 | Roof surface at 9-in-12 compared with 6-in-12, the pitch our base factor assumes |
| Roofing material | Installed cost per square |
|---|---|
| 3-tab asphalt (builder grade) | $375 – $550 |
| Architectural asphalt (most common) | $450 – $750 |
| Impact-resistant Class 4 shingle | $600 – $950 |
| Standing-seam metal | $1,000 – $1,800 |
Worked Examples for One-Story Greenville Homes
The same arithmetic the calculator runs, at standard pitch, for three common home sizes. A two-story home of the same size has a smaller roof and a lower range.
| Home size | Roof squares | 3-tab asphalt | Architectural asphalt | Class 4 shingle | Standing-seam metal |
|---|---|---|---|---|---|
| 1,500 sq ft | 19.8 | $7,400 – $10,900 | $8,900 – $14,900 | $11,900 – $18,800 | $19,800 – $35,600 |
| 2,000 sq ft | 26.4 | $9,900 – $14,500 | $11,900 – $19,800 | $15,800 – $25,100 | $26,400 – $47,500 |
| 2,500 sq ft | 33 | $12,400 – $18,200 | $14,900 – $24,800 | $19,800 – $31,400 | $33,000 – $59,400 |
Modelled from our published per-square ranges, rounded to the nearest $100. Not quotes. The cost guide's size table rounds a typical mix of one- and two-story homes, so its bands sit a little lower than a one-story example here.
What the Calculator Cannot See
A range from square footage is a starting point. A roofer on your roof will see what no calculator can, and these are the line items that most often move a Greenville bid.
- A second layer of old shingles to tear off, which adds labor and disposal
- Rotted decking, only found once the old roof is off
- Dormers, valleys, skylights and chimneys, each adding flashing and labor
- Ventilation work, which protects the shingle warranty
- Permit and inspection; see the Upstate roofing permit guide
Using the Number
If you have a bid, put your home's numbers in and see where it lands. Inside the band, compare scope line by line. Far below it, ask what is being left out. Far above it, ask what the roofer saw that drives the difference. Weighing a repair instead? Our guide to repair or replace has the cost math, and roof financing in Greenville covers paying for it.
Greenville Roofing Pages Behind the Numbers
Get the Number That Counts
The calculator gets you in the right range. For the exact figure, book a free inspection: a licensed local roofer measures your roof and gives you a written price, with no pressure and no obligation.
Schedule My Free InspectionRoof Calculator Questions
How accurate is this roof replacement cost calculator?
It applies our published Greenville per-square ranges to an estimated roof size, so it is as good as that size estimate. A measured roof in squares, entered directly, makes it tighter. The written quote after an inspection is what you actually pay.
How many squares is my roof?
For a one-story home at a standard pitch, roughly your living space times 1.2, plus 10% waste, divided by 100. A 2,000 sq ft ranch comes to about 26 squares. A roofer's measurement report gives the exact figure.
Does the calculator include tear-off and permits?
The per-square ranges are installed prices for a normal replacement. A second layer to remove, decking repair and complex flashing are extra line items a written estimate should name.
How Greenville Roofing Experts Works
We are a referral service, not a roofing company. Your request goes to one licensed South Carolina roofer serving the Greenville area, and the referral costs you nothing. See how we vet our pros for the bar that roofer has to clear, read about us and why this arrangement works, or check the answers to common roofing questions. For anything else, contact us.
Sources
Every price in this calculator is a per-square range from our Greenville cost guide (modelled market ranges, not quotes). The roof-size step is the same one our ZIP cost pages use.
- Greenville roof replacement cost guide (this site). Installed cost per square by material
- Roof replacement in Greenville (this site). Steep pitch or large roof premium