How do you calculate weld metal required?

Multiply total weld length by the weight of weld metal per inch to get deposited weight, then divide by the deposition efficiency. For 500 in at 0.027 lb/in and 85% efficiency, that is 13.5 lb deposited and 15.88 lb of filler to purchase.

What is the difference between deposited weight and filler metal purchased?

Deposited weight is the metal that stays in the joint (13.5 lb here). Filler metal purchased is larger because spatter, slag, and unburned stub ends are lost. The 2.38 lb difference is your loss allowance at 85% efficiency.

What is a good deposition efficiency?

It depends on process: stick (SMAW) runs roughly 60-70%, solid-wire MIG (GMAW) 90-98%, flux-cored (FCAW) 80-90%, and submerged arc (SAW) up to 99% with recovered flux. The 85% default is typical of self-shielded flux-cored work.

How do I find weight of weld metal per inch?

Use the weld cross-sectional area times steel density (0.283 lb/in3), or pull it from a weld metal table by fillet leg size. A 1/4 in fillet on steel is about 0.027 lb/in, which is the value used here.

Does this include the wire I waste on stub ends?

Yes — that loss is exactly what deposition efficiency captures. At 85%, every 15.88 lb spool yields about 13.5 lb of deposited weld; the remaining 2.38 lb is spatter, slag coating, and stub or burnback loss.

Why does my purchased quantity look higher than the deposited weight?

Because you never deposit 100% of what you buy. Dividing 13.5 lb by 0.85 inflates the figure to 15.88 lb. The lower your efficiency, the bigger that gap — at 60% the same weld would need 22.5 lb.

Welding & Fabrication calculator

Weld Metal Required Calculator

Weld metal required is the amount of filler — electrode wire, stick rod, or flux-cored wire — you must buy to deposit a given weld, after accounting for everything that never ends up in the joint. Estimators, welding engineers, and purchasing leads use it so a job has enough consumable on the shelf without over-ordering expensive alloy. The gap between deposited weight and purchased weight is real money: at 85% efficiency you pay for about 18% more metal than ends up in the weld. Getting this right is the difference between a quote that holds and one that bleeds margin to spatter, slag, and stub ends.

What this calculator does

Estimate filler metal needed from total weld length, weight of deposit per inch, and deposition efficiency.
Use it when sizing a filler wire or electrode order for a job and you do not want to short the line or over-buy a non-stock alloy.
It converts total weld length and per-inch metal weight into deposited weld weight, then divides by deposition efficiency to give the filler metal poundage you actually need to purchase.

Formula used

Deposited weld metal weight = total weld length × weight of weld metal per inch
Filler metal required to purchase = deposited weight ÷ deposition efficiency

Inputs explained

Total weld length: Sum all production welds on the part. Include fillet, groove, and plug welds.
Weight of weld metal per inch: Look up by weld size and joint geometry. About 0.027 lb/in for a 1/4 in fillet on steel.
Deposition efficiency: Use 95 for GMAW, 85 for FCAW, 65 for SMAW, 99 for SAW to convert deposited weight into wire purchased.

How to use the result

Use it when quoting a fabrication job, releasing a consumable purchase order, or sizing a wire spool reorder so the weld can be completed without a mid-run stockout.
It assumes one uniform weld size across the whole length and a single deposition efficiency; multi-pass joints, varying fillet sizes, or a mix of processes need to be broken into segments and summed.

Current U.S. benchmarks

The producer price index for steel mill products stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
Industrial electricity averages 8.66 cents per kWh across the U.S. (EIA, Apr 2026), up 5.5% from a year earlier. Energy-intensive steps carry this directly into unit cost.
U.S. iron and steel imports ran $2.1B in May 2026 (Census International Trade). The U.S. ran a trade deficit of $0.4B in the category that month. Import volumes are the pressure gauge behind tariff and reshoring decisions.
The U.S. has 53,790 fabricated metal products establishments employing about 1,441,471 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate weld metal required? Multiply total weld length by the weight of weld metal per inch to get deposited weight, then divide by the deposition efficiency. For 500 in at 0.027 lb/in and 85% efficiency, that is 13.5 lb deposited and 15.88 lb of filler to purchase.
What is the difference between deposited weight and filler metal purchased? Deposited weight is the metal that stays in the joint (13.5 lb here). Filler metal purchased is larger because spatter, slag, and unburned stub ends are lost. The 2.38 lb difference is your loss allowance at 85% efficiency.
What is a good deposition efficiency? It depends on process: stick (SMAW) runs roughly 60-70%, solid-wire MIG (GMAW) 90-98%, flux-cored (FCAW) 80-90%, and submerged arc (SAW) up to 99% with recovered flux. The 85% default is typical of self-shielded flux-cored work.
How do I find weight of weld metal per inch? Use the weld cross-sectional area times steel density (0.283 lb/in3), or pull it from a weld metal table by fillet leg size. A 1/4 in fillet on steel is about 0.027 lb/in, which is the value used here.
Does this include the wire I waste on stub ends? Yes — that loss is exactly what deposition efficiency captures. At 85%, every 15.88 lb spool yields about 13.5 lb of deposited weld; the remaining 2.38 lb is spatter, slag coating, and stub or burnback loss.

Last reviewed 2026-05-12.