Aluminum price per kg vs per meter can be compared only when the section’s mass per meter and the quotation scope are clear. To convert a price per kilogram into a price per meter, multiply by the agreed kilograms per meter for that profile.
Use the conversion to compare the material line, then compare the complete order separately. A lower converted material price does not necessarily give the lower delivered total when the offers include different additional charges.
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Identify the unit attached to each number
NIST’s SI units overview identifies the kilogram as a unit of mass and the meter as a unit of length. For a profile, kg/m expresses mass for each meter of length.
As an industry-document example, Capral’s extrusion capability table uses kg/m for section weight. This illustrates the unit; its table does not provide the mass or price for your particular ordered profile.
Ask the supplier which value supports the quotation: a nominal section mass, an agreed calculated mass or a measured billing quantity. Keep the answer with the offer so a later comparison uses the same basis.
Do not confuse the mass of one supplied bar with mass per meter. A total bar mass also needs its corresponding length before it can be used in a per-meter calculation. Keep the profile reference visible beside both numbers.
Aluminum price per kg vs per meter: a worked conversion
For this invented illustration, assume both offers cover the same profile with an agreed mass of 1.50 kg/m. All prices are hypothetical USD amounts, not current supplier quotations.
Offer A prices the material at USD 3.20/kg. Its equivalent material price per meter is:
3.20 USD/kg × 1.50 kg/m = 4.80 USD/m.
Offer B prices the same assumed profile at USD 5.10/m. Its equivalent material price per kilogram is:
5.10 USD/m ÷ 1.50 kg/m = 3.40 USD/kg.
Under those assumptions, A has the lower material-line price. You can see the same result in either unit: 4.80 is below 5.10 USD/m, and 3.20 is below 3.40 USD/kg.
The conversion works because both prices refer to the same agreed mass-per-length value. If a different section or billing basis is introduced, revise that input instead of carrying the old conversion into the new offer.
The complete invented order gives a different result
Now assume the order is for twenty uncut bars, each 6.00 m long. The delivered stock length is 20 × 6.00 = 120 m. Using the same assumed 1.50 kg/m gives 120 × 1.50 = 180 kg.
The material line is USD 576 for A and USD 612 for B. Suppose the agreed additional packing and delivery charges are USD 90 for A and USD 40 for B. These charges are invented solely for the example.
| Invented offer | Same 120 m order |
|---|---|
| A: USD 3.20/kg | 180 kg × 3.20 = USD 576 material. 576 + 90 charges = USD 666. |
| B: USD 5.10/m | 120 m × 5.10 = USD 612 material. 612 + 40 charges = USD 652. |
B now has the lower total for the stated scope, despite its higher converted material price. The example excludes tax and every charge not listed. It assumes no cutting, machining or later processing in either offer.
This is why the unit conversion and the full-order comparison should remain separate lines in your review. The first explains the material rate; the second answers the specific delivery being purchased.
Three quote checks before deciding
1. Confirm the product and quantity basis
Match the section drawing, alloy, temper, finish and supplied length across offers. Confirm whether quantities describe bars, meters, kilograms or finished pieces. Identify any difference that changes what you will receive.
Record whether the stated mass is used only for planning or also for invoicing. Ask how the billed quantity will be established. Resolve that commercial question with the supplier rather than treating an estimate as the invoice rule.
2. Confirm the currency and included scope
Keep the currency and quotation validity visible. List the agreed packing, delivery and processing charges with their quantity basis. Mark excluded items so an apparently similar offer is not compared against a broader scope.
If offers use different currencies, identify the agreed conversion basis for the comparison. Do not silently carry a rate from a previous enquiry into a new purchasing decision.
3. Confirm the actual material need
Compare the stock you must purchase for the approved part list. Finished-part meters and purchased-stock meters can differ because the cutting pattern includes losses and remaining lengths.
Use the mixed-length pattern example to review that stock requirement. Keep the material-price conversion separate from any assumption about how many bars fulfill the job.
Carry the material cost into cut-part planning
After choosing a quotation basis, connect the stock purchase to the planned cutting batch. Identify which material enters the order and how remaining stock is recorded for later use.
A price per meter of stock is not automatically a price per meter of accepted finished parts. Keep the finished quantities and the agreed manufacturing costs visible when reviewing the complete job. The profile mass guide explains a separate geometry-based planning calculation.
Questions buyers ask
Can I convert price per kg without the profile mass per meter?
You need a mass-per-length basis that matches the priced profile. Ask the supplier to confirm it before comparing the unit prices.
Is a kilogram price always cheaper?
Convert comparable material lines and then calculate the same complete order scope. The unit name alone does not determine the result.
Does a calculated profile mass set the invoice quantity?
Use the supplier’s agreed quotation and billing basis. Keep planning estimates separate from the quantity used to invoice the actual delivery.
What belongs in the cutting enquiry?
Provide the profile drawing, supplied stock length, material description, finished part list and quantities. Identify the approved stock plan and any inputs that still need confirmation.