Your factory just said “MOQ 500.”
You said “sounds good.” You have no idea what that means.
We should talk.
OptiSKUYou make the product.
We'll teach you the math.
require
better math
Right product. Right quantity. Right price. Right time. Right on.
Fluff is for puffers, not purchase orders.
Buy planning for optimized fashion brands. Small team, serious numbers: see what to order, what it really costs to land and the margin you keep, before you sign the PO, not after. Built to scale from your first drop to your fiftieth.
Free in your browser. OptiSKU models the numbers you enter. It doesn't predict a bestseller.
Pick a job. OptiSKU writes the prompt with your real numbers in it. Paste it into ChatGPT, Claude or any AI you use.
What do you need?Your numbers stay in this browser until you paste or send the prompt. AI can get things wrong: check its math against OptiSKU, and confirm duty rates with a licensed customs broker.
Three taps and you'll see the whole season: what to order, what it costs, and the margin you keep. Change anything after.
Season What you sell Sales goal for the seasonHave last season's numbers?
The black box below is your season: what the stock costs and the margin you keep after fees. Aim for 55% or more.
Stuck on a word? Tap Words at the top.
What you expect to bill this season across every channel, after discounts.
Each category's share of sales. Shares rebalance to 100%. Styles are set automatically from your MOQ; use − and + to override.
Split every category into good, better and best price points. Each tier gets its own styles, SKUs and PO lines.
Plan the way seasoned buyers do: start from the same season last year, what sold and how much of the buy it cleared. Enter last season's sales and sell-through for each category. Leave a row blank if it's new.
Each category's share of sales against its share of the open-to-buy. When a category takes more of your cash than it brings back in sales, it's working harder for less.
Work back from launch to see when each order has to be placed, then forward to see when cash leaves and comes back.
| Month | Out | In | Position |
|---|
Deposits go out at the PO, balances at shipment or 30 days after, freight and duty when goods land. Your site and marketplace sales come in week by week; wholesale is paid 30 days after delivery. Starting cash is zero, so the lowest point is the cash you need.
| Style | Color | Size | Units |
|---|
What you send to stores: every style with its colors, sizes, wholesale price, retail price and delivery window, built from the plan.
Add the factories you work with, then choose who makes each category. Each factory gets one PO per drop. The % is the added tariff on top of each product's base duty; we fill in example rates by country (since July 24, 2026: China 20%, which is the new 12.5% plus the older 7.5% China tariff on most apparel; Vietnam 12.5%; India, Bangladesh and Malaysia 10%). Some China items pay more. Check current rates with your broker.
POs are drafts at FOB prices from your plan. Confirm prices, sizes, labeling and delivery terms with each factory, and confirm HTS codes with a customs broker, before you send one.
Type each week's units, or import a report below. The latest week is on the right; scroll sideways for earlier ones.
Import sales from your store. Paste or upload a CSV export, like Shopify's sales by product variant SKU report. We need a product or SKU column and a units column. If there's a date column we sort sales into weeks, and if there's a net sales column we use your real prices.
Sell-through here counts wholesale units as sold when they ship to the store, the same way the plan does. Projections follow your plan's curve, scaled by how far ahead or behind you are (season to date blended with the last three weeks). On-hand stock counts only drops that have landed. Markdown suggestions use a rule of thumb that each 10% off lifts the weekly rate by about 20%; your own response will differ. A reorder only helps if it lands with season left to sell it.
Size a pop-up from the street up: how many people pass, how many walk in, how many buy, and what that means for stock, cash and profit. The product mix comes from your plan.
| If walk-ins are | Units | Sales | Profit |
|---|
A planning estimate, not a forecast. Walk-in and conversion rates vary widely by street, season and shop design; test your assumptions in the first weekend and update them.
A starting plan built from the rules above, not a forecast. Prices and costs come from each garment's example numbers and likely HTS duty; open a category on the Price tab to set your real ones, and the plan updates.
For reference: Kith's founder said in a September 2026 Complex interview that it makes about 60–65% on apparel and 45–50% on footwear it buys wholesale from other brands. Selling your own product, you have room to aim higher.
New footwear usually needs molds for the sole, one per size, often $1,500 to $5,000 each. A new sneaker design commonly needs $15,000 to $60,000 of tooling before the first pair. Using the factory's open (stock) sole avoids most of it.
One unit at full retail, followed down to what you keep. Discount and fees are averaged across everything you sell.
| Per unit | Amount | Share of retail |
|---|
Pick who buys it. We split your order the way those customers tend to buy.
Use your own sales. Enter last season's units sold by size, or paste or upload a CSV with a size and units on each line.
| Size | Even split | Your split |
|---|
Core colors carry the volume. Seasonal colors give the drop a point of view. Accents are small, fun and low-risk.
Describe the drop. Claude suggests 4 to 6 colors with roles and shares, using the trend library here. Uses your Claude account.
| Color | Buy | Demand | Low–high | At risk |
|---|
Loading the color library…
Color names come from the open-source color-names project (MIT license), loaded from jsDelivr. They're descriptive names for talking about color, not Pantone or dye-house standards.
Screen colors are approximations of Pantone TCX standards. Match physical swatches before you send colors to a factory.
Sources: Color of the Year 2026 (PPAI), NYFW AW26 (FashionUnited), LFW SS26 (FashionUnited), Pinterest Palette 2026 (B&T).
The plan
Saving keeps everything: this style, its colors and the whole season plan. Tick up to three to compare them.
Follow one style from tech pack to sell-through. The dates come from your plan; tick each stop when it really happens. Anything late or risky gets flagged on the road.
Fit this style in every fabric it comes in. A fit approved in one fabric doesn't carry over: weight, stretch and shrinkage all change it.
Dates are worked back from your launch date on the Plan tab's Timeline. Holiday closures and lead times are typical ranges, not promises; confirm ship dates with each factory in writing. Check-ins are kept in this browser.
40 calculators for the questions every buy raises. Type over any number.
You said “sounds good.” You have no idea what that means.
We should talk.
OptiSKUYou make the product.
We'll teach you the math.
Then it gets on a boat. Then off a boat. Then meets customs. Then meets your warehouse.
Your $16 would like you to meet landed cost.
OptiSKUYou make the product.
We'll teach you the math.
Congratulations on your 50% margin.
Unless that $20 was FOB. Add freight and duty and you're closer to 38%.*
*Assumes $1.60 a unit of freight and 16.5% duty, the US base rate for a cotton knit tee, on a $20 FOB. Added tariffs take it lower.
OptiSKUYou make the product.
We'll teach you the math.
because the MOQ was 300.
Why? No idea.
Correct.
OptiSKUYou make the product.
We'll teach you the math.
Amazing. Now tell us your gross margin, markdown rate, sell-through, inventory on hand and returns.
Still amazing? Now we know.
OptiSKUYou make the product.
We'll teach you the math.
Margin is what's left of the price after the product, shipping, duty, fees and discounts. Most of it is decided before you place the order. Here are five places it leaks, and where OptiSKU catches each one.
A $20 tee from the factory is closer to $24.90 once freight and duty are paid. Sell it at $40 and you keep 38%, not the 50% you counted on.
An even split leaves the smallest and largest sizes on the shelf, and whatever's left on the shelf ends up on sale.
Every color has a factory minimum. Too many colors means small runs, surcharges, and leftovers in the shades nobody picked.
Sell a 60%-margin piece at 15% off and you keep about 53%. Know how deep you can cut before a sale starts costing you money.
Air often costs five to ten times ocean per piece. Most rush shipping starts with a sample that slipped weeks earlier.
Work with a planner
Ideally ones that have read a cost sheet before.
The free tools take you most of the way. When you want a person to check your plan before you sign the PO, book a session with an OptiSKU planner: 15+ years in production, merchandising, SKU planning and international licensing at premium apparel brands.
1 hour · video call
$250
3 hours · two calls
$1,000
Every screen answers one question a founder asks before placing an order. Change an input and every number that depends on it changes with it.
Type a sales goal, pick what you sell and where you sell it, and get the season: how much to spend on stock, how many styles and colors, every size of every color checked against your factory minimums, the dates, the cash you'll need, and draft orders to confirm with each factory.
Pick from 111 products, from tees and polos to puffers, loafers and jewelry, and OptiSKU fills in its likely customs code and import duty. Add shipping, tariffs and fees to see what each piece really costs to land, the margin you'll keep, and how much you need to sell to get your cash back.
Turn one MOQ into a size run that matches how your customers buy. See the sales you'd miss and the stock you'd sit on with an even split.
Plan the color story, pull colors from published runway trend palettes and Pinterest's reported 2026 search trends, then split the buy by your own weights or past sales. Anything under the factory's color minimum gets flagged.
Save a version at $60 and another at $68. Try 300 units against 500. Keep the buy that makes sense and show it to your partner, investor or factory.
Once you launch, enter what sold each week. OptiSKU shows where every category is heading and tells you what to do next: reorder the winners, hold your price, or discount, and by how much.
Built for the AI age. Get your factory email and PO email written with your real numbers in seconds, or have AI pressure-test your plan and price. OptiSKU writes the prompt with your numbers in it. Paste it into ChatGPT, Claude or any AI you use.
Follow one style from tech pack to sell-through on a little road, with a walking tee that keeps pace with your dates. Tick each stop as it happens. Late samples, POs under MOQ, factory holidays and launch slips get flagged before they cost you a selling week.
Follow one garment from sketch to checkout. Every stop shows how long it takes, what it adds to the cost, and the words your factory, forwarder and stores will use.
Incoterms are the shipping terms on your quote. They decide where the factory's job ends and yours begins. FOB is the most common term on factory quotes. FOB and CIF are sea-freight terms; air quotes use FCA and CIP instead.
Costs use the garment's example numbers and likely HTS duty from the app; change them on the Price tab and this page follows. Duty codes and rates are planning guesses, not rulings; confirm with a licensed customs broker.
The words your factory, forwarder and stores use, in plain English, with what each one does to your margin. The same list is in the app: tap Words at the top of any screen.
No match. Try a shorter word.
Want the formulas and worked examples? Read the guides to landed cost, MOQ, margin vs markup, size curves, sell-through and IMU.
Twice a year we'll survey independent brands on what they pay, charge and sell through, by category and price point, and read it against public trend reports. Results are published only as totals, never by brand. Join the list to take part and get the first issue.
Contributors see the results first. We'll never share your numbers by brand.
We'll email you to confirm. You'll get product news and the Index, and you can unsubscribe any time. See Privacy.
Pricing, wholesale, cost, margin, quantity, inventory and cash. Each card answers one question with your numbers and says what the answer means.
OptiSKU's math comes from the books merchandisers learn on and the research the industry reads. Here's where each idea in the app comes from, if you want to go deeper.
The arithmetic and the six-month plan that every buying course teaches.
Bette K. Tepper · Fairchild Books
The standard on markup, margin, open-to-buy and markdown math.
In OptiSKU: The Fashion Math cards, initial markup and open-to-buy.
Richard Clodfelter · Fairchild Books
The buyer's job end to end, from the six-month plan to vendor negotiation.
In OptiSKU: The six-month plan in Plan › Timeline.
John Donnellan · Fairchild Books
Planning and controlling inventory from a merchant's point of view.
In OptiSKU: Stock-to-sales ratios and the stock plan.
Janice Ellinwood · Fairchild Books
A workbook for practicing a full buying plan by hand.
In OptiSKU: The season plan generator, a place to practice with your own numbers.
Michael Levy, Barton Weitz and Dhruv Grewal · McGraw-Hill
The broad retail text, with strong chapters on merchandise planning systems.
In OptiSKU: GMROI and inventory turn in the plan totals.
How UK retailers split the buyer and merchandiser roles and run the season week by week.
Rosemary Varley · Routledge
Range planning and how buying and merchandising work together.
In OptiSKU: Categories, price tiers and range building in Plan.
Tim Jackson and David Shaw · Palgrave Macmillan
UK fashion buying and merchandising practice.
In OptiSKU: The weekly sales, stock and intake view in Plan › Timeline.
Helen Goworek · Blackwell (now Wiley)
The fashion buyer's year, from range planning to sourcing.
In OptiSKU: Critical-path dates and POs.
How data changes the way assortments and inventory are planned.
Marshall Fisher and Ananth Raman · Harvard Business Review Press
Forecasting, reading early sales, markdowns and assortment, from Wharton and Harvard Business School.
In OptiSKU: The reorder reserve and the tracker's chase, hold and markdown calls.
The yearly read on where fashion is heading.
The Business of Fashion and McKinsey & Company · published every year
The most widely read annual report on the fashion industry, built from executive surveys and market data. The 2026 edition expects the industry to grow only in the low single digits again, and names tariffs, AI and resale among its ten themes. The 2021 edition argued that brands make too much and range too wide: it reported that only about 60% of garments sold at full price before the pandemic, and that long tails of unproductive SKUs drag on profit.
In OptiSKU: the long-tail check on your SKU list, the growth check against last season, and the full-price benchmark next to sell-through.
Read it at The Business of Fashion or McKinsey & Company.
Book links search WorldCat for libraries and editions near you. OptiSKU isn't affiliated with these authors or publishers. Benchmarks from The State of Fashion are as reported by The Business of Fashion and McKinsey & Company and press coverage of the reports.
The Season Trail · a game
One hero product, from moodboard to markdown. Survive the sample round, the big buy, a jammed port and Black Friday. Can you make it to spring?
Great product doesn't sell itself. A beautiful hoodie at a bad margin is still a bad margin. Keep the creative energy and make smarter decisions around it.
Draft for lawyer review. Not in effect.
These pages are working drafts so the site has a home for them. A lawyer should review and finish them before launch. Highlighted text is a placeholder to fill in.
OptiSKU is buy and SKU planning for fashion founders who are great at product and new to the numbers behind it. It turns a sales target into a season plan: what to spend, how many styles and SKUs, when to order, how much cash you'll need and the purchase orders to send.
The math comes from the books and research merchandisers learn on, listed on the Reading page, and every card shows its formula, so you can check the work.
[Founder note: a few lines on who you are, the brands you've built or worked with, and why you made OptiSKU.]
OptiSKU is made by [Company legal name], [city, state]. Contact: [email address].
Last updated: [date]
You can unsubscribe from any email with the link at the bottom, or ask us to delete your email address and survey answers at [email address]. We don't sell personal information. [Lawyer: add any state-specific rights, such as California's CCPA, and GDPR terms if you'll market to the EU or UK.]
Last updated: [date]
OptiSKU models the numbers you enter. It doesn't predict sales, and its results aren't financial, legal, tax or customs advice. You're responsible for the orders you place and the prices you set.
Codes and rates are likely matches for planning, not classification rulings. Added tariffs change often. Confirm codes and rates with a licensed customs broker or a CBP binding ruling before you price or order.
Trend colors, search trends and benchmarks are as published by their owners (Pantone, Pinterest, Lyst, The Business of Fashion and McKinsey) and may be out of date. OptiSKU isn't affiliated with or endorsed by them.
Your plans, numbers and color stories belong to you. [Lawyer: add license terms for anything users upload or submit to the Index.]
Don't misuse the service, try to break it, or copy it to build a competing product.
[Lawyer: warranty disclaimer, limitation of liability, paid-plan terms if Studio launches, and governing law and venue.]