Shopify Sell by Length: Minimums, Increments and Rolls

How to sell by length on Shopify (the short answer)

Shopify has no native sell-by-length unit, so you pick one of three routes: (1) treat 1 unit as 1 metre or foot in the quantity field, (2) use a length-input or calculator app, or (3) create fixed cut-length variants. Route 1 suits simple whole-unit sales, route 3 suits a handful of standard lengths, and route 2 suits custom lengths, multiple rules or larger catalogs.

A few terms used throughout this guide:

• Minimum: the shortest length you will cut (for example 2 m).
• Increment: the step between allowed lengths (for example 0.5 m).
• Maximum: the longest length per order, often tied to what is left on a roll.
• Roll or spool: the full stock unit you cut from or sell whole.

The Shopify Community thread on selling by length documents the same limitation: merchants end up relabeling Quantity as metres and adding min/max rules with an app. That works up to a point. The rest of this guide shows where it stops working.

Decide what your sellable unit is

Before touching an app, decide what one unit of your product means. Every later rule (minimum, increment, rounding, stock) depends on this choice.

Per-length vs per-roll vs per-spool selling

• Per length: the customer chooses how much to buy, and you cut it from a roll. Typical for fabric, hose, rope and cable.
• Per roll: the customer buys the whole roll. Simple, and no cutting rules are needed.
• Per spool or fixed pack: the customer buys full spools or fixed lengths, such as trim in 8 ft pieces. Here the job is rounding up to whole packs.

Many stores mix these: custom lengths up to a limit, then a full-roll product above it.

Pick a base unit and an increment

The base unit is what Shopify counts as 1. The increment is the smallest step you are willing to cut and pack accurately. Choose an increment you can actually measure at your cutting table, not the finest one a customer might type.

Product type	Base unit	Typical minimum	Typical increment
Fabric	1 m or 1 yd	1-2 m	0.5 m or 0.25 yd
Hose	1 ft or 1 m	3-5 ft	1 ft
Cable or rope	1 m	1-5 m	1 m
Trim or edging	1 yd or 1 ft	1 yd	1 yd, or full spool

These are typical ranges, not rules. Set them from your own cutting process and supplier packaging.

Check catalog price and stock units match

Shopify catalog prices drive what the customer is charged. If you sell fabric at $14.00 per metre, the product price is $14.00 and the quantity represents metres. You are not replacing line prices with an arbitrary number, so the unit the price refers to and the unit the quantity counts must be identical.

Do the same check for inventory. If a roll holds 100 m, stock should read 100 (metres), not 1 (roll). Otherwise you will oversell, or block orders while stock is available.

Method 1: Use quantity as length (and where it breaks)

This is the most common starting point, and it is fair to say it works for simple whole-metre sales.

Setup: price per metre, relabel Quantity

1. Set the product price to your price per base unit, such as $14.00 per metre.
2. Set inventory in the same unit, so a 100 m roll is 100 in stock.
3. Edit your theme text so the selector says "Metres" or "Length (m)" instead of "Quantity". How you do this depends on your theme, usually through theme language settings or a small code edit.
4. State the unit in the product title or description, for example "Price per metre, cut to order".

Add minimum and maximum with an order limits app

An order limits or min/max app can enforce a minimum (say 2 m) and a maximum (say 50 m) per order. Some also support a step value such as increments of 1. Check the specific app's listing for what it supports, since features vary. This setup is enough if customers only ever buy whole metres within a fixed range.

The limits: whole units only, no multi-cut orders, confusing cart

Shopify quantities are whole numbers, so this method has predictable failure points:

• Fractional lengths: a customer who needs 1.2 m cannot enter it. They round up to 2 m, or contact you.
• Multiple cuts: a customer who needs 2 pieces of 1020 mm, or 30 pieces of 200 mm, cannot express that in one number. Total length loses the cut list.
• The 10 mm trick: some merchants set the base unit to 10 mm, so a quantity of 102 means 1020 mm. It allows finer lengths, but the cart shows "102", the packing slip shows "102", and the price per unit looks strange next to the product page. Staff and customers both misread it.
• Inventory edge cases: stock counted in 10 mm units produces large numbers that are easy to mis-key.

If your customers need whole metres only and never specify cuts, stay with Method 1. If you are receiving questions like "can I get 1.2 m?" every week, it is time to look further.

Method 2: Fixed cut-length variants and why they run out

When variants are enough (a handful of standard lengths)

If you sell three to six standard lengths, variants are clean. A hose sold as 10 ft, 25 ft and 50 ft assemblies, each with its own price and SKU, needs no app. Stock, packing slips and returns all work the way Shopify intends.

Variant limits and catalog upkeep

Variants stop being practical as soon as customers want arbitrary lengths. Take a product cut from 100 mm to 6000 mm in 10 mm steps: that is (6000 - 100) / 10 + 1 = 591 possible lengths. Each would need its own variant, price and SKU. Shopify also caps the number of variants per product (check its current documentation for the limit), and every price change means editing hundreds of rows.

The same maths applies to a catalog. Ten products with 50 lengths each is 500 variants to keep consistent.

Email cut lists and quote forms: the hidden cost

When merchants cannot express lengths in the store, they fall back on notes fields, emails or quote forms. The costs are operational rather than technical:

• Customers type lengths in mixed units ("1.2m", "4 ft", "approx 120 cm"), and someone has to interpret each one.
• A manual price has to be calculated and the order edited or re-created.
• A mismatch between what was asked and what was cut turns into a return on a product you cannot resell.
• Support time grows with order volume instead of staying flat.

None of this is a reason to avoid custom cuts. It is a reason to move the rules into the cart.

Method 3: A length calculator with rules enforced in the cart

A length calculator takes the shopper's input, converts it into whole Shopify quantities using your rules, shows an estimated total, and keeps the measurement attached to the cart line.

What the calculator should do: input, conversion, rounding, limits

Whatever app you evaluate, check that it covers:

1. Length input in the unit the customer thinks in (metric or imperial), with conversion to your base unit.
2. Rounding to your increment, or up to full lengths, rolls or spools.
3. A minimum and maximum, enforced at the cart and not just on the product page.
4. The measurement visible in the cart, so quantity edits do not break the link between the length and the quantity.
5. Pricing from Shopify catalog prices, so checkout and reporting stay consistent.

There are more options than we can list here. Our custom price calculator app buyer's guide lists the questions worth asking before you install any of them.

Set minimum, increment and maximum

The three rules work together. A fabric product might use a 2 m minimum, 0.5 m increment and 50 m maximum. A shopper typing 1.2 m is brought up to the minimum, a shopper typing 3.2 m is rounded up to 3.5 m, and a shopper typing 80 m is stopped at the maximum.

Rounding up (never down) protects you. Rounding down means the customer receives less than they asked for.

Round up to the roll or spool

When the product is sold in fixed pieces, rounding is about packages instead of increments. Trim sold in 8 ft lengths cannot be sold as 41.8 ft, so the calculator converts the required length into whole pieces. The same logic applies to spools and to rolls with a fixed width, as in roll width and cuts for artificial turf.

This differs from area-based products, where coverage per box matters. If you are selling by area instead, see how to sell by square foot on Shopify.

Keep the measurement visible in the cart

The biggest advantage over the quantity-as-length trick is clarity. The customer sees what they entered and the quantity it produced. If they change the quantity in the cart, the displayed measurement should update with it, rather than showing a stale length that no longer matches the order. Test this in every app you trial, because it is where weaker setups tend to fail.

What Shoperize Price Calculator does and doesn't do

Shoperize Price Calculator is one option. It is live on the Shopify App Store. Based on what is confirmed today:

• It turns shopper area, dimensions, length, volume or weight into purchasable Shopify product quantities, coverage and estimated totals.
• Merchants configure unit conversion, waste, package coverage, rounding, limits and product assignments.
• Measurements stay in the cart, and coverage updates when quantities change.
• Rules can be created manually, from templates, or as editable AI drafts (plan limits apply).
• The Free plan supports one published area calculator on up to three products.
• Length, volume and weight inputs, minimums, maximums and increments, and fixed-width roll planning are on the Pro plan ($9.99 a month or $99.99 a year, with a 14-day trial).

What it does not do: charges follow your Shopify catalog prices, so it does not replace line prices with arbitrary amounts. Check the current App Store listing for up-to-date plan details before you commit.

Worked examples

These examples are illustrative. Use your own prices, increments and stock units.

Fabric: 3.2 m requested, 0.5 m increment, 2 m minimum

Shopify quantities are whole numbers, so make one unit equal the increment: the catalog price is $7.00 per 0.5 m unit ($14.00 per metre). See also how to sell fabric by the yard or metre with a calculator.

1. Shopper requests 3.2 m.
2. The minimum is 2 m, so the request passes.
3. The increment is 0.5 m, so 3.2 m rounds up to 3.5 m.
4. Shopify quantity: 3.5 m is 7 units of 0.5 m.
5. Estimated total: 7 x $7.00 = $49.00.

If the shopper had typed 1.2 m, the rule would bring it up to the 2 m minimum (4 units), for a total of $28.00.

Hose: 47 ft needed, sold in 25 ft lengths, 5% allowance

Here the hose is sold in 25 ft lengths and the customer wants an allowance for trimming.

1. Required length: 47 ft.
2. Add 5% allowance: 47 x 1.05 = 49.35 ft.
3. Round up to whole lengths: 49.35 / 25 = 1.974, so 2 lengths.
4. Order: 2 x 25 ft = 50 ft.

Trim: 38 ft of edging sold in 8 ft lengths with 10% waste

1. Required length: 38 ft.
2. Add 10% waste: 38 x 1.10 = 41.8 ft.
3. Divide by length per piece: 41.8 / 8 = 5.225.
4. Round up: 6 pieces.
5. Order: 6 x 8 ft = 48 ft.

The customer pays for 6 pieces, not 38 ft. Showing both numbers in the cart avoids a dispute later.

Roll-limited product: 100 m roll with a 50 m maximum per order

Suppose you cut from a 100 m roll and cap each order at 50 m so that one customer does not take the whole roll.

1. Shopper requests 120 m.
2. The maximum is 50 m, so the cart does not accept 120 m.
3. The shopper either reduces the length to 50 m or less, or contacts you for a larger order or a full roll.

If you prefer to sell a full 100 m roll above a certain length, offer it as a separate product at a roll price and mention it next to the length field. That keeps stock counted in metres on the cut-length product and in rolls on the other.

Setup checklist before you publish

Product and price setup

• Set the price per base unit (per metre, per foot, per piece).
• Set stock in the same unit.
• Write the unit into the product title or the first line of the description.
• Assign the calculator or rules to the products that need them, and leave fixed-length products as normal variants.

Rules and rounding

• Choose a minimum, increment and maximum you can cut reliably.
• Decide whether you round up to the increment, the piece or the roll.
• Add a waste or allowance percentage only where customers expect it, and say so on the page.

Test the cart and checkout as a customer

Place test orders for each of these cases:

1. A length below the minimum.
2. A length that is off the increment (for example 3.2 m with a 0.5 m step).
3. A very large length above the maximum.
4. A quantity edit in the cart after adding the product.
5. The same flow on a phone, since many shoppers measure and order from mobile.

Update packing slips, product copy and returns policy

Cut goods usually cannot be resold, so say so before checkout. A clear line such as "Cut-to-length items are final sale unless faulty" saves arguments later. Make sure the picker sees the length in the order details, not just a quantity. Selling by weight is a separate approach with its own unit and rounding rules, so do not mix the two on one product.

Selling by length in POS vs online

POS apps for weight and length

Some length and weight apps are built for in-person selling at a counter through Shopify POS rather than for the online store. If you sell both ways, check each app's listing for which channels it supports.

Online store considerations

This guide covers the online store, where the shopper is alone with the product page. That is why cart-level rules matter: there is no staff member to correct a wrong length before the order is placed. Decide per channel, and do not assume a POS setup will carry over to the storefront.

Next step

If you want to try length rules and rounding in your own store, you can install Shoperize Price Calculator from the Shopify App Store. Product details are at calculator.shoperize.com, and setup help is at help.shoperize.com.

Frequently Asked Questions

Can Shopify sell fractional lengths like 1.2 m?

Not natively, because Shopify quantities are whole numbers. You can redefine the base unit (for example 10 cm or 10 mm) or use a calculator app that converts a typed length into whole quantities using your increment and rounding rules. Either way, decide whether 1.2 m should round up to 1.5 m or be accepted as is.

How do I set a minimum and increment?

Use an order limits app or a calculator app that supports minimum, increment and maximum rules. Set the minimum to the shortest piece you will cut and the increment to the smallest step you can measure reliably. Then test with off-increment values to confirm the cart rounds up as you expect.

What about multiple cuts in one order?

A single quantity field cannot hold a cut list, such as 2 pieces of 1020 mm. For a few standard lengths, use variants so each cut is its own line item. For custom cuts, you can add the same product several times with different lengths, or use an app that stores each measurement with its cart line, and check the current listing for how it handles this.

How is selling by length different from selling by weight?

Length is a measurement the customer specifies and you cut to, while weight depends on scales and often on an actual weighed result. Length rules revolve around minimums, increments and roll limits, and the price is per metre or foot. Weight rules need a unit such as kg or lb and a tolerance, so treat them as a separate setup.