Skip to main content
Calcimator

Solar-Ready Roofing Calculator

Evaluate whether your roof can support solar panels based on age, area, panel count, and weight.

Inputs

years
sq ft
lbs

Results

Total Load

840 lbs

≈ 5 adults

Structurally Adequate

Yes

Load (PSF)2.4 psf
Reinforcement NeededNo
Roof Life Remaining20 years
Roof Coverage18%
How to Use This Calculator
  1. Enter roof area (sqft) and the target solar panel load (PSF load).
  2. Set current roof age and select roofing material.
  3. Review total panel load in lbs, load per sq ft, and structural adequacy rating.
  4. If reinforcement is flagged, consult a structural engineer before proceeding with solar installation.
  5. Replace roofs older than 10 years before adding solar panels to avoid costly panel removal later.

How the result changes with Number of Panels

Number of PanelsTotal LoadStructurally Adequate
11462 lbsYes
361,512 lbsYes
652,730 lbsYes
903,780 lbsYes

What each input means

Roof Age
How old is your current roof
Roof Area
Total usable roof area in square feet
Number of Panels
How many solar panels you plan to install
Panel Weight
Weight of each panel including mounting hardware

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Roof Age = 5, Roof Area = 2000, Number of Panels = 20, Panel Weight = 42 = 4 input(s) provided
  2. Calculate Total Load
    Total Load
    840 = 840
  3. Calculate Structurally Adequate
    Yes = Yes
  4. Calculate Load
    Load
    2.4 = 2.4
  5. Calculate Reinforcement Needed
    No = No

Engine last updated . Checked against 2 independently-derived tests — how we verify calculators.

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Roofing (Advanced)

Metal Roofing Calculator

Calculate the number of metal roofing panels, ridge cap, and total square footage needed for your roof.

Roofing (Advanced)

Roof Replacement Timeline Calculator

Estimate when your roof will need replacement based on material, climate zone, age, and maintenance history.

Roofing (Advanced)

Roofing Labor Calculator

Estimate crew size, project duration, and labor cost for a roofing job based on roof squares, complexity, and tear-off.

Structural Engineering

Snow Load Calculator

Calculate flat roof snow load, sloped roof snow load, and drift loads per ASCE 7 using pf = 0.7CeCtIpg.

More in Construction & Building Trades.