Free trade calculators
Free calculators for trade contractors — no login needed. Results are estimates only. Always verify with a licensed professional.
Roofing Square Calculator
Calculate roof area, squares, and shingle quantities from dimensions and pitch.
Use calculator →HVAC BTU Calculator
Estimate heating and cooling load for any room with climate zone and insulation inputs.
Use calculator →Voltage Drop Calculator
Calculate voltage drop and verify NEC 3% compliance for any electrical circuit.
Use calculator →These calculators provide rough estimates for planning purposes only. Results should not be used as the sole basis for any professional or purchasing decision. SMBData LLC makes no warranty as to accuracy. Always consult a licensed contractor or engineer before proceeding.
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