Maintained Markup (MMU) Formula
How apparel brands calculate maintained markup — the final margin that survives markdowns, allowances, and returns — and the channel benchmarks that signal a healthy season.
What Maintained Markup measures
Maintained markup is the margin that actually landed — the percentage of net sales that remained gross margin after markdowns, allowances, and returns. If IMU is the margin you start with, MMU is the margin you keep.
MMU % = (Net Sales − COGS) ÷ Net Sales × 100The gap between IMU and MMU is the story of the season. A small gap means the plan held. A big gap means markdowns, returns, or cost overages consumed margin the pricing architecture was supposed to protect.
Worked apparel example
A DTC brand sold $840K in net sales (after returns) for the Tops department in a season. COGS for those units was $370K.
MMU % = ($840K − $370K) ÷ $840K = 56.0%
IMU for the department was 62%. The 6-point gap is the cost of the season: markdowns taken, allowances granted, returns reduced net sales, and cost overages on a few styles. A healthy IMU-to-MMU gap for DTC runs 6–10 points. Ten-plus points signals markdown trouble.
MMU of 56.0% is strong — markdowns and returns stayed in line with plan.
Benchmark ranges
Failure modes we see
MMU measured only at season close. By the time the report lands in the post-mortem deck, the season is done. The planning team finds out in March that Fall's MMU missed by 4 points — and every decision that caused it is locked in.
Specific patterns:
- No in-season MMU tracking. MMU drift only surfaces at hindsight. In-season reads of running IMU + markdown would flag the trajectory weeks earlier.
- Returns excluded. Brands use gross sales, not net sales, in the MMU calculation. Returns can be 5–25% of gross in DTC apparel — excluding them inflates MMU by 3–6 points.
- Wholesale allowances missed. Off-invoice allowances, chargebacks, and markdown money reimbursed to accounts often land in a different GL and get missed in the MMU roll-up.
How RetailNorthstar handles MMU
MMU runs live in a connected planning system. As markdowns are taken, returns processed, and allowances booked, the system recalculates MMU against plan at department, class, and style level. Drift is flagged before it becomes hindsight.
The IMU-to-MMU gap is the single best measure of how well the merchandising plan held. A tight gap means buy depth, pricing, and assortment balance were well-matched to demand. A wide gap means the plan broke somewhere — and connected data is the only way to trace it to the specific styles, sizes, or channels that caused it.
Related formulas
- Initial Markup — the starting margin MMU drains from
- Markdown % — the primary drain on IMU-to-MMU
- GMROI — combines MMU with inventory efficiency
See how RetailNorthstar tracks IMU-to-MMU drift live by department, class, and style.
Book a Demo →Frequently asked about Maintained Markup % (MMU)
What is the MMU formula?
MMU % = (Net Sales − COGS) ÷ Net Sales × 100. Net sales is the critical input — it is post-return, post-allowance, post-markdown, which is why MMU is the honest margin measure for a season.
What is a healthy IMU-to-MMU gap?
For DTC, a 6–10 point gap between IMU and MMU is typical and healthy. Over 10 points signals heavy markdown, fit issues driving returns, or cost overages. Under 6 points is unusual and usually means under-marked or extended full-price sell.
Do returns count against MMU?
Yes. Returned units reduce net sales, which is the denominator in MMU. A brand using gross sales instead of net sales will overstate MMU by 3–6 points in DTC apparel.
Can MMU be tracked in-season?
Yes, and it should be. Most brands only review MMU at season close, by which point every decision that caused the miss is locked in. In-season MMU — recalculated weekly as markdowns, returns, and allowances land — lets teams intervene before hindsight.