Should larger sizes cost more and by how much?
If a large uses more material than a small, price it from its own cost and your margin target, then compare that with simply adding a flat amount.
Many sellers add a flat amount for bigger sizes: Rs 50 for L, Rs 100 for XXL, and so on. It feels tidy. But a flat top-up can quietly shrink your margin on the sizes that cost you the most. Let us look at one example and see what the numbers say.
The setup
Say you sell a cotton kurta. The small size costs you Rs 200 to make, counting fabric, stitching, thread, tag and packing. The large uses extra fabric and a little more stitching time, and costs Rs 250. That is Rs 50 more.
You want a 40 percent margin on the selling price. The formula is cost divided by (1 minus margin). For 40 percent, that is cost divided by 0.6.
- Small: Rs 200 divided by 0.6 is about Rs 333.
- Large: Rs 250 divided by 0.6 is about Rs 417.
So the large needs to sell about Rs 84 higher than the small to keep the same margin, even though it only costs Rs 50 more to make. That surprises people. The reason is that your margin is a share of price, so when cost goes up, price must rise by more than the cost to protect the same share.
What a flat Rs 50 top-up does
Now try the common shortcut. Keep small at Rs 333 and add Rs 50 for large, which gives Rs 383.
- Profit on large is Rs 383 minus Rs 250, which is Rs 133.
- Margin on large is Rs 133 divided by Rs 383, roughly 35 percent.
You aimed for 40 percent and got 35. At the formula price of Rs 417 you would earn Rs 167 on each large, so the shortcut costs you Rs 34 a sale. Over hundreds of orders, and with a sizeable share of customers picking large, it adds up. Flat top-ups are acceptable when the material difference is small and your margin has room. They are risky when the larger size also needs more shipping weight or more packing.
Do customers accept a bigger gap?
Often yes, but not always. Shoppers compare sizes in the same listing. A jump of Rs 84 for one size up may feel steep for a garment where they think "it is the same shirt". Here you have choices:
- Price the large from its own cost and explain the reason in the description, for example more fabric and a longer cut.
- Hold the gap smaller and accept a slightly lower margin on the large, balancing it with a higher margin on the small.
- Keep one price for all sizes and set it from your most expensive size. This is simple, and the small size carries a bigger margin.
None of these is wrong. What matters is that you pick one on purpose, with the numbers in front of you.
Count more than material
When you work out the cost of each size, include the pieces that scale with size:
- Courier weight, since a larger parcel can fall in a higher weight slab. See shipping-weight-slab-trim-example for how that works.
- Packaging that is bigger or heavier.
- Stitching or making time, if larger pieces take noticeably longer. pricing-your-own-labour-per-item covers that part.
A quick routine
- Work out cost for each size separately.
- Divide by one minus your target margin to get a formula price.
- Compare the formula price with a flat top-up and see the margin each gives.
- Choose, then round to a clean figure such as Rs 349 and Rs 429, and recheck the margin after rounding.
Doing this once for your whole size range takes ten minutes and protects the margin on your biggest sizes.