CutSizeGenie is a Shopify app for fashion and apparel e-commerce brands that unlocks revenue from out-of-stock sizes using virtual inventory and size mapping. It improves size availability on Shopify product pages without theme edits.
How it works

Shopify size mapping + virtual inventory, end-to-end

CutSizeGenie helps fashion brands recover sales lost to out-of-stock sizes. It does this by safely using your jump sizes (like M, XL) to keep neighbour sizes (like S, L) available — when your operations can fulfil via alterations/cut-size.

Install CutSizeGenie → Safety & guardrails Taruni case study
In one line
Keep PDP sizes available, without buying more stock.
Virtual inventory is controlled by thresholds, caps and scoping rules.
Step 1: Map sizes Step 2: Auto-restock Step 3: Consume safely Step 4: Logs & visibility Step 5: Controls
Step 1

Define your size mappings

You tell CutSizeGenie how your warehouse can fulfil sizes in reality. Example: if S is sold out, you can fulfil from M via alteration.

Example mapping rules
  • S → M (when S is OOS, borrow from M)
  • L → XL (when L is OOS, borrow from XL)
  • Optional: scope by product / collection / category
Read jump sizes strategy → See use cases →
What happens in Shopify

Mappings connect Shopify variants (not themes)

CutSizeGenie works at the inventory layer using Shopify Admin APIs. No theme edits, no Liquid snippets required.

Merchant action
Select the source size variant(s) and target size variant(s), then save mapping.
App stores
Mapping is stored in the app database with the product/variant reference and guardrails.
Best practice
Start with your top 20–50 styles where alterations are already part of operations, then scale.
Step 2

Auto-restock “virtual” sizes

When a mapped target size hits 0 on Shopify, CutSizeGenie checks the source size inventory and can push limited availability to the target size to keep PDP conversion healthy.

Trigger example
Target size S becomes 0 → app checks mapped source size M. If safe limits allow, the app updates S inventory to a small value (virtual availability).
Behind the scenes

Safety checks before any virtual push

Inventory threshold
If source size inventory is below your threshold, the app will not push virtual stock.
Max share cap
The app won’t allocate beyond the cap you set for that mapping, preventing aggressive sharing.
Scope rules
Only products/collections/categories you allow will be eligible for virtual inventory.
Location behavior
If you use locations, virtual stock can be applied only to the right location (e.g., DC).
Thresholds explained All safety controls
Step 3

Orders consume real stock safely

If a customer orders a virtual size (example: S), the actual inventory consumption happens from the mapped source size (example: M). This keeps accounting clean and prevents uncontrolled stock creation.

Example
Customer buys size S (virtual) → app consumes from size M (real), and records the mapping used for ops visibility.
Why this matters

Your operations stay predictable

Picking clarity
Warehouse knows which source size to pick. Alteration steps are aligned with your SOP.
No “double counting”
The source size is always protected by thresholds and caps so it isn’t drained accidentally.
Tip
Run virtual inventory only on SKUs where your tailoring team is comfortable. Exclude complex designs or fragile fabrics.
Read the alteration workflow guide →
Step 4

Logs & visibility for teams

Virtual inventory only works long term when teams have visibility. CutSizeGenie logs virtual pushes and virtual orders so everyone stays aligned.

Virtual push logs
Tracks when virtual availability was granted to a target size and from which source size.
Virtual order logs
Tracks which orders consumed inventory virtually so ops can action alterations cleanly.
Outcome
Your merchandising, performance and ops teams can review impact and exceptions without guessing.
More case studies FAQ
Step 5

Controls: pause, exclude, or roll back anytime

Your sizing strategy changes with seasons, collections and operational capacity. CutSizeGenie is built to be easy to control.

Disable mapping per product/collection
Turn off a mapping when a style is no longer alteration-friendly or when inventory is low.
Change thresholds/caps anytime
Increase thresholds during peak seasons to protect stock and reduce operational load.
Exclude categories where it’s not safe
Keep virtual inventory limited to fashion/apparel categories where alterations are acceptable.
Uninstall = stop logic
If you uninstall the app, the automation stops and Shopify returns to default inventory behavior.
Install CutSizeGenie → Compare with “Back in stock” apps Safety page
How it works page for CutSizeGenie Shopify app. Explains step-by-step flow: Step 1 define size mappings; Step 2 auto-restock virtual sizes when target is zero; Step 3 consume real stock from source size on order; Step 4 logs for virtual pushes and virtual orders; Step 5 controls via thresholds, caps, scoping rules, location behaviour, pause/disable/uninstall.