Free Field Tools & Charts
Resources
Calculators and printable charts for sheet metal and HVAC, built for the jobsite and the shop.
Field calculators
Works on your phone. Imperial or metric.
Duct SizerRound, rectangular and oval sizes from airflow and a friction rate or velocity.
Rectangle · Round · OvalEquivalent sizes, aspect ratio and fit-a-depth for tight spots and linear plenums.
Velocity & Pressure Drop TablesRound and rectangular duct capacity by friction rate, and any one size across a range of airflows.
Duct WeightSheet area and weight by size, length, gauge and material.
Bend AllowanceBend allowance, bend deduction and flat blank size.
Diameter · CircumferenceStretch-out and cut length for round pipe, or diameter from a circumference.
OffsetsSeam heights and filler pieces for parallel offsets, two-elbow 90s and offsets off a floor or wall.
Hanger StrapsCut lengths for clamshell hangers, wall straps and hangers with one long end.
Reference charts
Free printable PDFs.
