Free tool · Published NJ prices

Roof Replacement Cost Calculator for South Jersey

A planning range for your roof in under a minute, built on published New Jersey prices, with every assumption and source shown. No email needed to see the number.

Updated September 2026 · 4 min read · Written by M&J Roofing

GAF Master Elite® certified
4.8★ on Google · 222 reviews
Family-owned since 2007
NJ-registered & insured · HIC #13VH12363400
Free inspections & written estimates
Offices in Blackwood & Turnersville

Key takeaways

Published New Jersey rates put architectural shingles at $7–$15 per sq ft installed, plus $1–$2 per sq ft for each layer torn off.
For a 2,000 sq ft roof (20 squares) that works out to about $16,000–$34,000 with one layer removed; basic 3-tab shingles run about $8,000–$18,000.
Roof size, pitch and the condition of the deck underneath move the price more than anything else.
A quote is only comparable if it names the products and prices deck repair per sheet before work starts.

In this guide

What a new roof costs in South Jersey

The calculator above runs on one set of published New Jersey rates. Here is the same maths laid out by roof size, so you can see the whole picture at once. Each figure includes tearing off one existing layer and hauling it away.

Installed price with one layer torn off, before steep-roof or deck repairs
Roof size	3-tab asphalt shingles	Architectural shingles	Metal roofing	Flat roof membrane
15 squares (1,500 sq ft)	$6,000 – $13,500	$12,000 – $25,500	$15,000 – $28,500	$6,000 – $13,500
20 squares (2,000 sq ft)	$8,000 – $18,000	$16,000 – $34,000	$20,000 – $38,000	$8,000 – $18,000
25 squares (2,500 sq ft)	$10,000 – $22,500	$20,000 – $42,500	$25,000 – $47,500	$10,000 – $22,500
30 squares (3,000 sq ft)	$12,000 – $27,000	$24,000 – $51,000	$30,000 – $57,000	$12,000 – $27,000
35 squares (3,500 sq ft)	$14,000 – $31,500	$28,000 – $59,500	$35,000 – $66,500	$14,000 – $31,500

A roofing square is 100 square feet of roof surface. Roof area is always bigger than the floor area underneath it, because the roof overhangs the walls and slopes. A 2,000 sq ft ranch with an ordinary pitch usually has around 25 squares of roof.

These ranges are wide because the published rates are wide. Where your roof lands inside the range depends on the things below. As a cross-check, the 2025 Cost vs Value report from the Journal of Light Construction priced a full 3,000 sq ft asphalt shingle replacement with two skylights at $34,338 in the Philadelphia market, and the same roof in standing-seam metal at $56,652. Both sit inside the calculator’s ranges for a roof that size.

Why two quotes for the same roof can be thousands apart

It is usually scope, not margin. Put two quotes side by side and the gap nearly always comes from one of these:

Tear-off versus overlay. One contractor strips the roof to the deck; the other lays new shingles over the old layer. The overlay is cheaper today and hides whatever is underneath.
New flashing versus reused. Chimney, wall and step flashing can be replaced or bent back into place. Reused flashing is where many “new roof” leaks start.
Underlayment and ice barrier. Synthetic underlayment across the whole deck, and ice-and-water shield at the eaves, valleys and penetrations, cost money. Some quotes include both, some neither.
Ventilation. A balanced ridge and soffit system extends shingle life and is often a condition of the manufacturer’s warranty.
The deck rate. One quote names a price per sheet of plywood if rot turns up; the other says nothing, which leaves the number open once the roof is off.

If one contractor won’t itemise, that is your answer.

Six things that move the number

Roof size

Roofs are priced per square. Waste, ridge and hip caps and starter strips all scale with the roof, so a bigger roof costs proportionally more, not less.

Pitch

A roof a crew can walk is quicker and safer to work on. Anything steeper needs harnesses, roof jacks and more time, which is why the calculator adds a steep-roof allowance.

Layers

Every layer that comes off has to be stripped, loaded and dumped. Plenty of older South Jersey homes already carry two. M&J Roofing explains how many layers New Jersey allows.

Deck condition

This is the one nobody can price from your driveway. Soft or rotted sheathing has to be replaced before anything goes on top, and it only shows once the old roof is off. That is why a fair estimate states a per-sheet rate in advance.

Penetrations and shape

Chimneys, skylights, dormers, valleys and walls all need flashing detail. A cut-up roof costs more than a simple gable of the same area.

Material

Architectural shingles are the standard on South Jersey homes now. Metal and premium shingle lines cost more up front and last longer; flat sections over porches and additions use a membrane instead.

What a written estimate should include

If a quote is one number on one line, you can’t compare it to anything and you can’t hold anyone to it. Every item below should be on paper:

Squares: the measured roof area, not a guess from the street
Tear-off and disposal: how many layers, and who pays for the dumpster
Named products: shingle line, underlayment, ice-and-water shield and ridge vent, by brand
Deck replacement rate: a per-sheet price agreed before anyone finds rot
Flashing: chimney, skylights, valleys and walls, and whether it is new or reused
Warranty terms: manufacturer coverage and workmanship coverage, stated separately
Payment schedule: no legitimate roofer needs the full amount before starting
The contractor’s NJ registration number, which New Jersey requires on the contract

New Jersey law adds its own list for any home improvement contract over $500, including the insurance certificate and your three-day right to cancel. Our NJ contractor license lookup guide covers it line by line.

Four pricing tactics worth walking away from

A price over the phone. Nobody can price a roof they haven’t measured or walked. A phone number is a sales tactic, not an estimate.
A big deposit before materials are ordered. Large upfront payments are how storm chasers disappear.
“Today only” pricing. A discount that expires when the salesperson leaves your kitchen was never real.
No named products. “Lifetime shingles” means nothing without a manufacturer and a product line.

How to use the calculator’s number

Treat it as a sanity check, not a price. If a quote lands well below the range, ask what’s missing: a layer left on, reused flashing, no ice barrier. If it lands well above, ask for the itemised breakdown and check the product line and the scope.

For the contractor’s side of the same question, M&J Roofing has a breakdown of what a roof costs per square foot in New Jersey. Not sure you need a new roof at all? Start with roof repair vs replacement, and see what a South Jersey roof replacement includes.

Sources: HomeAdvisor, New Jersey roof replacement costs (updated June 17, 2026); Angi, roof replacement cost (updated March 5, 2026); HomeGuide, roof decking replacement cost; Journal of Light Construction, 2025 Cost vs Value Report, Philadelphia; NJ Division of Consumer Affairs, Home Improvement Contractor Compliance Checklist.

Free · No obligation

Talk to a Local Roofer

Free inspection, written estimate, no obligation. Or call 856.725.5759.

FAQs

Frequently Asked Questions

Straight answers on cost, permits, storm claims and choosing a roofer in New Jersey.

Still have a question?

Talk to M&J’s office in Blackwood. Monday to Friday, 8am to 4:30pm.

How accurate is this roof cost calculator?

It gives a planning range, not a quote. The rates are published New Jersey installed prices, and the roof area is estimated from your home’s size, storeys and pitch, so the result is only as close as that estimate. A measured roof, the real number of layers and the condition of the deck are what turn a range into a price, which is why a written estimate needs an inspection.

How do I work out how big my roof is?

If you have a previous estimate or an aerial roof report, use its measured area (squares × 100 = square feet) in the calculator’s “I know the roof size” option. If not, the calculator estimates it from your living space: roof area is larger than floor area because of the overhangs and the slope, so a 2,000 sq ft ranch with a medium pitch has roughly 2,500 sq ft of roof.

Is a layover cheaper than a full tear-off?

Up front, yes: you skip the labour and disposal of removing the old layer. Over the life of the roof it’s usually the worse value. Nobody can inspect or repair the deck under a layover, the extra weight matters on older framing, and some manufacturer warranties require a tear-off. It’s only possible at all when the roof has a single existing layer.

What does deck replacement add to a roof replacement?

Published installed rates run about $2 to $5 per square foot of deck replaced. On a typical roof, replacing 10% of the deck adds several hundred to over a thousand dollars. Agree a per-sheet price in writing before work starts, so the number can’t change once the roof is open.

Will insurance pay for my new roof?

For sudden damage from a covered event such as wind, hail or a falling tree, often yes, less your deductible. For wear and age, generally no. Our storm damage and insurance claims guide walks through the process.

Homeowner Guides

Get a Straight Answer, Free

A free inspection with photos and a written estimate. If a repair will hold, that’s what we’ll quote.