💡 In this article we will look at:
How to use the Size Calculator for aggregated & individual product analysis
The difference between the 2 curves: True rate of sale & Sales unit curve
The logic behind true rate of sale that analyses size performance only when it's in stock
Intro to the Size Calculator
We're excited to announce the brand-new Size Calculator - a new and enhanced way to find your perfect size curve. 🎉
The tool helps you calculate the ideal size curve for any product or group of products with 2 analysis methods: True Rate of Sale curve or Sales Units curve.
Based on the data available through the Size Calculator, you can then take actions and apply it to your future product ranges and know you will be in stock in more sizes for longer.
How to use the size calculator?
There are 2 ways you can analyse sizes, at aggregated or individual level.
Aggregated Level Analysis (Recommended for category)
Refine your product selections
This should answer the question: what products are you looking to analyse?
On your Products page, use the Launch Date & Add Filter options to narrow down your products selections for analysis
For example, you are looking to analyse size performances of Mini Dresses for Style Arcade brand that have launched in the last 12 weeks.
Sub Category filter = Mini dresses
Brand filter = Style Arcade
Launch date filter = May 2023 (see FAQ #1 on why we recommend a launch filter instead of a date filter)
Go to the Size Calculator
Select the size calculator from the actions button
Choose between True Rate of Sale Curve or Sales Units Curve for your analysis
True Rate of Sale Curve calculates how much a size can sell when it is in stock, therefore excluding out of stock weeks.
Choose your size convention & time period
Sales Units curve shows the the week on week variances which also includes out of stock weeks. Read more about the differences between the two here.
Choose from the number of weeks active & size convention
Calculate the ideal buy units
Click into Calculate Buy Units button
Enter your total buy quantity and Style Arcade will tell you how much to buy per size. You can edit the quantity for each size individually.
Copy or download the ideal size curve and voila!
Product Level Analysis
Simply click into the Product on your Products page, and select Size Calculator in the product detail page and repeat steps 3 - 5 above to start your analysics
How is the data calculated?
When using the size calculator Style Arcade needs to calculate:
1. What products to analyse?
Style Arcade analyses products that fit the following criteria:
Products that had sizes in stock for at least one week during the period analysed.
Product example | S | M | L | XL |
week 1 | ✅ | ✅ | ✅ | ✅ |
week 2 | ✅ | ✅ | ✅ | ✅ |
week 3 |
| ✅ | ✅ | ✅ |
week 4 |
| ✅ | ✅ | ✅ |
The example above shows a time filter applied to week 3 & 4.
In this scenario we have no sales/stock data (identified by ✅) for size S in the time period but we can see size S has had activity in previous weeks. This product would be excluded from the analysis because Style Arcade cannot recommend a curve when it has no data for size S.
2. How to group the size conventions?
Size conventions are created based on a size having had sales and/or stock to indicate the size that existed for that product.
Sizes are grouped into conventions at the product level. See table below where the ✅ indicates there have been sales or stock over the time period being analysed.
Style Arcade uses the convention with the highest number of products as the default and shows this one first.
| S | M | L | XL | Convention |
Product A | ✅ | ✅ | ✅ | ✅ | S-XL |
Product B | ✅ | ✅ | ✅ |
| S-L |
Product C |
| ✅ | ✅ | ✅ | M-XL |
3. What is the True Rate of Sale %?
Style Arcade uses the true rate of sale to calculate the rate of sale when in stock %
Not sure how the true rate of sale is calculated? Check out our article here.
| True rate of sale before returns | True rate of sale before returns % |
S | 2 | 17% |
M | 5 | 42% |
L | 4 | 33% |
XL | 1 | 8% |
Total | 12 | 100% |
4. What is the Available To Sell %?
This is calculated using the metric called available to sell (ATS) - a sum of current stock on hand + sold units at the size level converted to a percentage
| Available to sell (ATS) | Available to Sell % |
S | 20 | 17% |
M | 50 | 42% |
L | 40 | 33% |
XL | 10 | 8% |
Total | 120 | 100% |
FAQs 🔎
1. Why is it recommend to use the launch date filter when you use the Size Calculator?
To analyse a group of more recent products so that you get the most up-to-date size curve. If you only apply a time filter it will include old products that have old sizes curves.
2. Why does the Size Calculator not analyse all products within the filter search
Not all products within the filter selection will fit the criteria to be analysed. The criteria to be analysed are:
Products that had each size in stock for at least one week during the period analysed. Style Arcade cannot include products if we have missing data for some sizes.
Products are grouped into size conventions so Style Arcade can accurately recommend a new size curve. Not all products in your search will have the same size convention.
3. How do I test the Size Calculator logic?
You can test the size calculator logic in Rollups by creating a report that looks like the one below. The true rate of sale before returns mix % will match the sold units % in the size calculator. Make sure you are analysing the correct products using the search bar.
4. How can I edit my buy units by size?
Once you have the correct size curve you can click to “calculate buy units” and input the total buy units or edit sizes individually.
5. How can I swap between True rate of Sale or Sales units curve?
You can swap your curve by clicking on the titles of the curve at the top.
6. What is the difference between Sales Units curve and the True Rate of Sale curve?
There are a few differences between the two:
a. True Rate of Sale Curve is driven by the metric called the true rate of sale to recommend an ideal size curve.
True rate of sale calculates how much a size can sell only when the size is in stock. See the image below which shows an example of how the true rate of sale is calculated for one product across size level:
b. On the Size Calculator, you can apply a date range when using True Rate of Sale Curve. This is ideal for analysing core products or excluding promotional periods. Whereas in the Sales Units curve, you will need to choose from a number of weeks to analyse as it includes out of stock weeks.
Note: if you select a time period where a product has no sales or stock data for one or more sizes, Style Arcade cannot recommend a curve and will therefore exclude this product.
7. What’s the difference between the Sales curve % and the Buy curve % in True Rate of Sale Curve?
The sales curve is the recommended curve using the true rate of sale enhanced logic.
The buy curve is reflective of the buy units by size. These will differ if you edit the buy units by size.
8. What if I want to apply a date range when using the Sales Units curve?
The date range filter on the top left will not impact the Sales Units curve. The curve will only change when you choose a different No. of weeks active.
This is because by filtering to certain dates, the data is chopped in relation to the filter. This can mean products are removed from the analysis because one or more sizes were out of stock for that period and therefore did not sell.
If Style Arcade does not have the data for one or more sizes for any given product it cannot recommend a curve because it will be wrong.
The table below shows an product example that would be excluded as a result of the time filter has been applied to week 3 & 4. In this scenario we have no sales/stock data for size S in the time period but we can see size S has had activity in previous weeks.
Product example | S | M | L | XL |
week 1 | ✅ | ✅ | ✅ | ✅ |
week 2 | ✅ | ✅ | ✅ | ✅ |
week 3 |
| ✅ | ✅ | ✅ |
week 4 |
| ✅ | ✅ | ✅ |
Got any questions? Feel free to reach out to our in-app chat for assistance! 🤩