Welding Calculator Pro (USA)

Welding cost per linear foot = (Electrode cost + Shielding gas cost + Labor cost + Overhead cost) ÷ Total weld length in feet. Our calculator computes weld metal volume from the leg size, calculates electrode weight needed (accounting for deposition efficiency and stub loss), estimates time from deposition rate, and sums all costs. This matches the cost estimation method used by AISC and major USA fabricators.

Heat input (HI) = (Voltage × Amperage × 60 × η) ÷ (Travel Speed × 1000), measured in kJ/in. It measures the thermal energy delivered per unit length of weld. AWS D1.1 and ASME Section IX require heat input calculation for Welding Procedure Specifications (WPS) because excessive heat input can reduce toughness and cause grain growth in the HAZ. Essential variable changes of ±10% in heat input require requalification per ASME IX.

Per AWS D1.1:2020 Table 3.2, minimum preheat depends on the material group, thickness of the thickest member, and hydrogen level. For Group I steels (A36) with low-hydrogen electrodes: no preheat below 3/4″, 50°F minimum for 3/4″ to 1-1/2″, 150°F for 1-1/2″ to 2-1/2″, and 225°F above 2-1/2″. For Group V (A514/T-1), preheat starts at 150°F for thickness over 1/4″ and goes up to 450°F for thick sections. Use our preheat calculator for exact values.

Electrode needed depends on weld size and process. For a 1/4″ fillet weld using SMAW (E7018, 60% deposition): weld volume = 0.0313 in³/ft, weld weight = 0.088 lb/ft, electrode needed ≈ 0.17 lb/ft (including stub loss). For GMAW (97% deposition): only 0.091 lb/ft of wire needed. Our calculator gives exact values for any leg size and process combination.

Standard GMAW shielding gas flow rates per AWS standards: 35-50 CFH for shop welding with C25 (75% Ar/25% CO₂), 40-60 CFH for outdoor/windy conditions. GTAW typically uses 15-25 CFH. Excessive flow can cause turbulence and pull air into the shield (over-gassing). Use a flowmeter calibrated in CFH, not a gauge. Our gas calculator computes total consumption and cost for any job duration.

SMAW (Stick): Flux-coated electrode, portable, versatile, 60% deposition efficiency. GMAW (MIG): Continuous wire feed + shielding gas, 95-98% deposition, high productivity. GTAW (TIG): Tungsten electrode + hand-fed filler, highest quality, slowest. FCAW (Flux-Cored): Tubular wire with internal flux, gas-shielded (FCAW-G) or self-shielded (FCAW-S), excellent for outdoor structural work. Each process has specific parameter ranges — use our Parameters Calculator for recommendations.

For fillet welds: Volume (in³/ft) = (Leg² × 0.5 × 12) ÷ 1728. Weight (lb/ft) = Volume × 490 lb/ft³ (steel density). Example: 3/8″ fillet = 0.141 in³/ft = 0.069 lb/ft of weld metal. For V-groove welds, calculate the cross-sectional area from groove angle, root opening, and thickness, then multiply by length and density. Our calculator handles both weld types automatically.