How-to guides
Practical, step-by-step guides for apparel and retail planning — free, vendor-neutral, and paired with the tools and templates you can use to apply them.
How to calculate maintained markup (MMU) →
Maintained markup (MMU) is (net sales − cost of goods sold) ÷ net sales: the markup actually kept after markdowns, promotions, employee discounts, shrink and damages. The formula in dollars and percent, what belongs in reductions and what does not, the identity with initial markup derived in both directions — MMU % = IMU % − reductions % × (100% − IMU %) and IMU % = (MMU % + reductions %) ÷ (100% + reductions %) — and shown agreeing on one class, reductions on net sales rather than original retail, MMU against gross margin (cash discounts and workroom costs) and against cumulative markup, style, class and department figures at retail weights rather than averaged, full-price against marked-down units, period against season-to-date, reading it against plan in-season with early and late reductions, dollars against the rate, channels, carryover and pack-away, shrink and returns, how it reaches open-to-buy, eight ways it misleads, and what changes in each of eight verticals.
What is open to buy (OTB)? →
Open to buy is the receipt budget still available for a period: planned closing stock + planned sales + planned reductions − opening stock − on order, at retail or at cost. What OTB means in business and in a store, why it exists, each term defined, the formula at cost and in units, a worked four-month class, how it moves inside a month, negative OTB and the levers, the chase reserve, OTB against a buy plan, a merchandise financial plan and a WSSI, grain and ownership, nine common errors, and what changes in each of nine verticals.
How to calculate sell-through rate →
Sell-through rate is net units sold ÷ (net units sold + ending on hand). Which base to divide by and why opening stock alone or receipts alone misleads, units against value across a class, weekly against season-to-date, full-price against total, size-level and door-level reads summed rather than averaged, when high sell-through is the problem, the links to weeks of supply and stock-to-sales, reading it against receipt timing and a plan curve built from the style’s own plan, the launch read, what it should trigger (chase, hold, re-allocate, markdown), how a gap reaches open-to-buy, returns, transfers and shrink, carryover and continuity items, wholesale accounts, reviewing a report, nine ways it misleads, and what changes in each of eight verticals.
How to calculate initial markup (IMU) →
Initial markup (IMU) is (retail − cost) ÷ retail. The formula on retail and on cost and converting between them, IMU against maintained markup and gross margin, deriving the margin target from the plan, solving the IMU a maintained-markup target and planned reductions require, the markdown room an IMU leaves, the landed cost lines that belong in the cost base, blending a class IMU at retail weights rather than averaging, the markup the open purchases must carry, cumulative markup once receipts land, price points, reorders, wholesale and direct, own brand, reading the season back against plan, seven ways an IMU misleads, and what moves IMU in each of ten verticals.
How to allocate merchandise to stores →
Merchandise allocation splits a committed buy across stores, sizes and ecommerce. Initial allocation against replenishment and transfers, the inputs (store grades and clusters, capacity, presentation minimums, size curves, rate of sale), grading doors at the gaps, a worked allocation of one style to ten graded doors with a DC reserve, why a flat split fails, push against pull, timing and floor sets, sizing the reserve, a short buy, reading the first two weeks and choosing the release rule, multiple deliveries, carryover, the handoff to replenishment, new styles from like-for-like proxies over in-stock weeks, size-level allocation and prepacks, ecommerce alongside doors, telling an allocation error from a buying error, transfers, the season exit, scoring the allocation, and the unit of allocation in each of ten verticals.
The retail inventory method (RIM) →
The retail inventory method values stock at retail and converts it to cost with the cost complement. The stock ledger line by line, choosing the pool one complement can describe, the conventional and average-cost variants, period versus cumulative basis, a fully worked season with the physical-count restatement, RIM against the cost method and weighted average, the mixed-margin break that no reconciliation can find, channel and transfer treatment, and what the cost column hands back to the next merchandise plan.
How to calculate GMROI →
GMROI is gross margin dollars divided by average inventory at cost. Where markdowns, shrink and freight sit in the numerator, why a two-point average misreads a seasonal build, annualizing from twelve months over thirteen points, GMROI against margin, turn, GMROII and GMROF, deriving your own hurdle instead of importing one, using it to set category depth and open-to-buy, raising a low reading lever by lever in cost order, and what the ratio cannot see.
How to calculate lead time →
Lead time is the calendar days from PO issued to goods sellable. Choosing the start and end events, the segment identity, attributing a slip to decision, vendor, transit or destination, lead time vs cycle time vs OTD, turning variability into a buffer in days or units, back-scheduling a T&A calendar from the in-store date, and setting the chase window, reorder point and OTB reserve.
How to reforecast in-season →
Re-project the remaining season from actuals to date — restate closed periods, project the balance by category from run-rate, trend and last year’s shape, rebuild closing stock and re-solve open-to-buy — then read the over- and under-bought periods and work the levers in the order they expire: cancel, push, re-allocate, markdown, chase, hold.
How to set a sales plan →
The pre-season sales plan is the root of OTB and everything downstream. Build it top-down (last year restated, times a growth view) and bottom-up (category and door), reconcile the two, split comp from non-comp, phase it across the season, and set the re-plan cadence before trading starts.
How to build a markdown plan →
Budget markdowns pre-season inside the sales plan, phase the spend to the season exit, set triggers on sell-through and forward cover, ladder the depth, work exit dates back from the season end, and reconcile the spend in the WSSI.
Retail planning conferences 2026–2027 →
NRF Big Show, Shoptalk, RetailClub AI Festival and RE:PLAN compared for planning teams — what each event is, who it serves, planner relevance, and a decision framework for one budget slot, two, or a team split.
NRF Big Show 2027 for merchandise planners →
NRF states 41,000+ attendees, and it is not a planning conference. What the Big Show actually offers a planner — an expo-floor and market-intelligence event, not a curriculum — how to triage the floor in two to three days with pre-booked vendor meetings, who should attend versus send one person, and the regional editions.
Shoptalk for planning teams →
Spring (Las Vegas, ~10,000 attendees per Shoptalk) vs Fall (Nashville, 3,500+ leaders, moved from Chicago in 2026), honestly compared for a planning seat — no planning curriculum; the value is the vendor landscape, AI programming, the meetings program, and cross-functional exposure.
RetailClub AI Festival 2026: a guide for retail planning teams →
The first full-scale edition of the Shoptalk and Groceryshop founders’ AI conference, after their smaller inaugural 2025 retreat — who on a planning team should attend and who should skip it, what the four content pillars mean for forecasting and inventory work, how to scout a young event, and how to turn three days into an internal readout.
How to measure forecast accuracy →
A forecast accuracy number means nothing without its metric, its grain and its horizon. What MAPE, WAPE, bias and a tracking signal each measure, where each one breaks, why aggregation and stockouts flatter the number, and the reporting spec that makes an accuracy figure comparable to itself.
How to build a margin bridge →
An ordered waterfall from the margin you costed to the margin you banked — landed-cost variance, markdowns, shrink, returns and wholesale deductions, each with its arithmetic and one named owner.
How to find the minimum buy depth a size run can support →
A correct size curve still breaks if the buy is too small. Calculate the depth floor below which tail sizes round to one unit per door, and the four levers that fix it.
How to plan a dropship channel →
Dropship is neither a booked commitment nor your own forecast — plan it as an availability policy with a service-level buffer, where cancel rate rather than fill rate is the failure metric.
Planning depth for a rental assortment →
Size a fleet from peak concurrent bookings and turnaround time, why utilisation has a ceiling below 100%, and why cycles to payback replaces sell-through as the decision metric.
How to plan a private-label range against the national brand →
Own-brand units substitute for branded ones rather than adding to them — so cut the branded buy deliberately, and watch margin rate rise while margin dollars per unit fall.
How to set open-to-buy (step by step) →
The open-to-buy formula, a worked apparel example, what negative OTB means, and how to keep it aligned to receipts and POs.
How to build a T&A calendar →
Map every production milestone backward from the in-store date, with an owner and lead time on each step, so a slip surfaces the moment it happens.
What is a WSSI? →
What the weekly sales, stock & intake plan is, the three lines it tracks, and the identity behind it: closing stock = opening stock + intake − sales.
How to read a WSSI, week by week →
An operational walkthrough on a worked 12-week grid — the cover line, finding the stock-out and overstock weeks, phasing intake, and when the grid is lying to you.
OTB vs WSSI: what’s the difference? →
How the open-to-buy budget and the weekly trading view differ, when to reach for each, and why most planning teams end up needing both.
How to plan receipt flow →
Phase intake across a season — solve receipts from the inventory identity, turn period dollars into dated in-store deliveries, size a chase reserve, and work the escalation ladder when a delivery slips.
How to plan a peak-concentrated season →
When most of a season lands in a few weeks — measure the concentration by channel, phase against the curve, set the last-receipt date, size a reserve lead time can actually deliver, and pre-decide the shoulder.
How to build a buy plan →
Turn OTB, assortment decisions, and demand assumptions into a line-by-line buy — with costs, margin, channels, and delivery timing attached.
How to calculate size curves →
How to build size ratios from history and translate total style/colour demand into size-level buying quantities that match how a style actually sells.
Line plan vs assortment plan →
What each plan decides — the range you will offer versus where it goes and in what depth — and how the two connect to buying and production.
Retail math formulas →
A practical formula library covering OTB, sell-through, GMROI, inventory turnover, markdown, margin, and weeks of supply, each with a worked example.
How to plan for returns →
Gross demand versus net demand, why return lag makes returns a phased inflow rather than a percentage haircut, where resaleability stops, what the resaleable share does to receipts and open-to-buy, and how to set and revise a return assumption without whipsawing the plan.
How to plan wholesale and DTC together →
One production buy against two demand signals — booked wholesale and forecast DTC. The commitment calendar, one shared reserve instead of two buffers and the condition it depends on, minimum order quantities on the combined line, the scarcity rule, and reconciling one buy to two margin statements.
Safety stock for seasonal assortments →
The standard safety stock formula assumes stationary demand, continuous replenishment, item history and independent SKUs — a seasonal assortment breaks all four. Where each assumption fails, what to use instead, and where the formula still holds.
How to plan a replenishment program →
A replenishment program plans a rate, not a season total. Building the reorder point over lead time plus review period, sizing min and max, the four things that break a clean trigger, the test a seasonal style has to pass to graduate into the core, and the phase-out rule that ends a continuity item when no season end will.
Looking for analysis and best practices? See Insights.