How many squares of shingles do I need?
Roof area, squares, bundles, underlayment and tear-off weight — from footprint and pitch. Free, no email required to see the math.
Your inputs
Footprint at the eaves, including overhangs.
Rise in inches per 12" of run.
You'll need
Assumptions (tap to adjust)+
The math, in plain English.
We start with the footprint of the house — length times width at the eaves — and stretch it by a pitch multiplier, because a steeper roof has more surface than the floor under it. That's your roof area. Divide by 100 to get roofing squares, add waste for cuts (more on a hip roof, with all its angles), and you've got the number a supplier quotes from.
Everything else hangs off the squares: three bundles of architectural shingles per square, a roll of synthetic underlayment per four squares, drip edge around the full perimeter in 10-foot sticks, and ridge cap along the peak. Step and kickout flashing at walls and chimneys are job-specific, so they're not counted here.
Tear-off weight is where roofing surprises people. Old asphalt shingles run about two and a half pounds a square foot per layer, so a modest house sheds a couple of tons. That's what sizes the dumpster. While the roof's open is also the time to check the soffit and fascia — rot there is common in the Pacific Northwest and cheap to fix when the crew's already up there.
Roofing questions
What is a roofing square?+
One hundred square feet of roof surface. Roofers price and order by the square, not the square foot, so a "20-square roof" is 2,000 square feet of shingles. Architectural shingles come three bundles to the square.
How do I measure roof pitch from the ground?+
Pitch is rise over a 12-inch run. From the ground, hold a level horizontally against the gable end in a photo and count the rise, or use a phone level app on a ladder at the eave: set a 12" mark along the rafter tail and measure straight up. Most Vancouver-area homes fall between 4/12 and 8/12; 6/12 is a safe default if you can't tell.
Do I need to tear off the old roof?+
WA/IRC R908.3 typically allows two layers max — confirm with the permit office. If there's already a second layer, it's coming off. Even with one layer, tearing off lets the crew inspect the deck, replace rotten sheathing, and lay new underlayment. An overlay is cheaper today and usually costs more at the next replacement.
How does CRM Services handle roofing?+
Through our subcontractor model: CRM Services, LLC stays your single point of contact and manages the job, while a dedicated roofing crew does the installation. You get a dual warranty (ours on the project, theirs on the workmanship) and the bulk pricing that comes from the volume we send them. Rot repair, siding and gutters are handled by our crew on the same visit.
What does roofing cost per square in Vancouver, WA?+
These ranges reflect the Vancouver, WA / Portland metro market — outside the area, treat them as a rough guide. A typical range for architectural shingles, tear-off included, is several hundred dollars per square, climbing with pitch, layers, and how much rotten decking turns up. Want a firm number? Request a free estimate and we'll price it by the square with every line shown.
What size dumpster do I need for a roof tear-off?+
Figure the tons first — this tool does that from your roof area and layers — then check the Dumpster Size Calculator. A single layer on a typical house is usually a 10- or 15-yard box; two layers or a big roof pushes you to 20.
Related services
Other free tools
Get a free estimate for roofing.
You've got the numbers — we've got the crew. Free onsite consult and a line-item quote, usually same day to 48 hours, depending on scope.