Welding Electrode and Wire Consumption and Labour Budget Check Calculator

What goes wrong when deposited weld metal is ordered as electrode weight

When a fabrication job with a fixed drawing comes in, such as brackets, base plates or frames, the first decisions are how much electrode or wire to buy and how many welder hours to allow.
If the deposited weld metal worked out from the drawing section is written down as the purchase quantity, or labour is priced on arc-on time alone, both materials and labour run short.
Up to a third of the purchased weight of stick electrodes is scrapped as stubs and slag, and a welder spends more of the day fitting parts, chipping slag and changing position than with the arc burning.

This welding electrode and wire consumption and labour budget check calculator works out deposited weld metal from approved fillet leg sizes or groove dimensions, weld length and count.
With deposition efficiency, deposition rate, operating factor and separate fit-up and inspection hours, it calculates the consumable weight and packs to buy, arc time and total labour hours, shielding gas, flux and labour cost in one pass.
Enter a subcontract quote’s consumable weight and hours and it also shows whether the quote listed only the deposited weight or priced labour on arc time alone.

The welding formulas are international (TWI Job Knowledge); the VAT and gas cylinder handling notes below are based on Korean rules checked on 2026-10-25, so outside Korea apply your own tax and safety rules.

Main features from weld metal to quote check

Agree on what each input means

• Weld metal: use the density of the weld metal made by the filler, not the parent plate.
  Pick a TWI table value such as carbon steel 7.86 g/cm³, 304 stainless 7.92 g/cm³ or aluminium 5052 2.65 g/cm³, or enter your own.
  
• Deposition efficiency: weld metal deposited divided by the consumable weight used.
  It includes stub, spatter, slag and fume losses; enter supplier data or a site measurement.
  
• Deposition rate: weld metal deposited per arc hour (kg/h).
  It can differ from the melt-off rate, so check that the supplier figure is on a deposited basis.
  
• Operating factor: the share of working time with the arc on.
  It excludes set-up and assembly, so enter fit-up, tack and inspection hours separately.
  
• Overweld allowance: metal welders lay beyond the drawing size.
  The cap height h of grooves is already in the section formula, so add only other excess; the default is 0%.
  
• Pack weight, stock and prices: enter the net weight and price of one spool or box and the stock of the same grade.
  Leave prices blank to calculate quantities only, with costs shown as not calculated.
  

Electrode and wire consumption formulas

A 1 mm² section running 1 m is 1,000 mm³, which is 1 cm³, so multiplying the drawing section in mm by the length in m gives cm³ directly.
TWI notes that weld metal weight and filler metal weight are not necessarily the same and gives a factor per process to multiply the weld metal weight by.
The TWI cost article states that its duty cycle figures do not include set-up or assembly time, so the calculator adds separate hours.

TWI gives 80–90% for mechanised TIG and MIG/MAG and 70–85% for mechanised FCAW.
As a deposition example, a 1.2 mm MAG wire deposits about 1.2 kg/h at 120 A and about 8 kg/h at 380 A, so time changes greatly with current even within one process.
The table is a reference range, not a site standard, and the calculator only flags inputs outside it for review.

Joint cross-section formulas and the TWI example

t is the plate thickness, b the bevel angle of one side, g the root gap, f the root face and h the cap height.
The TWI formula adds two bevel triangles, the root gap rectangle and a cap of width W = 2c + g times height h divided by 2; with a root face f of 0 it matches the calculator.
A double-V groove is calculated one side at a time and added, as TWI describes.

Step-by-step use

1. Choose the weld metal and the welding process.
   Changing the process resets the default shielding gas, and the TWI reference factor, operating factor and deposition range appear under the process field.
   
2. Enter the deposition efficiency, deposition rate, operating factor, separate fit-up, tack and inspection hours and labour rate confirmed from supplier data or site measurement.
   If you have no efficiency data yet, choose the TWI reference factor and replace it with a measured value later to clear the review note.
   
3. Copy each weld’s joint type, dimensions, length of one weld and count from the approved drawing and WPS.
   Use the direct cross-section option for sections without a formula, such as U grooves.
   
4. Enter the spool or box weight and price, stock, gas flow with cylinder content and price, and the flux ratio for submerged arc.
   Choose VAT included only if prices and the quoted total include Korean 10% VAT; with any other VAT rate, enter net prices and choose VAT excluded.
   
5. If you have a subcontract quote, enter its consumable weight, hours and total and read the quote table and items to check.
   Save the TXT order sheet and confirm the WPS, pack size and efficiency with the welding engineer and supplier before ordering.
   

Fictional worked example

These values come from the calculator’s pure functions and are fictional; they are not product data, recommended welding settings or market prices.

How to read the results

How much consumable changes with the process

Welding 10 m of the TWI example joint (3.993 kg per metre) deposits 39.93 kg of weld metal whatever the process.
The consumable to buy, however, depends heavily on the loss factor of each process; the table below changes only the TWI reference factor.

Buying only the deposited weight of stick electrodes leaves 19.97 kg, a third of the need, short.
Submerged arc loses only 0.80 kg of wire, but TWI gives about 1 kg of flux per kg of weld metal (about 39.93 kg), so always enter the flux ratio.

Korean VAT and gas cylinder handling rules

Three practical situations

Limits and checks before ordering

1. Check that efficiency and deposition rate are for the same wire diameter, current and position.
   Using flat-position values for vertical or overhead welding leaves the time badly short.
   
2. The most accurate operating factor comes from logging arc time and attendance over a period.
   Without records, stay toward the low end of the TWI reference range.
   
3. Confirm with the supplier that spool and box weights are net and that the cylinder content is the supplier’s converted volume.
   The approximate CO₂ conversion comes out about 0.5% high.
   
4. Check the drawing again that fillets on both sides, repeated parts and back welds after gouging are all entered as counts or separate welds.
   Missing a single line shortens both the order and the labour.
   

Frequently asked questions