Step-by-step plan: How to index prices with a CBS price index
To adjust your sales prices, you can use a price index from Statistics Netherlands (CBS). Learn which price indexes there are and how to use a CBS index in this checklist.
What is a price index?
A price index shows how prices are changing and whether products and services are becoming more expensive or cheaper. A well-known example is the Consumer Price Index (CPI). A price index allows you to compare prices with those at an earlier point in time, such as last year. If the price index rises, prices have gone up on average. If it falls, they have gone down. Businesses use the price index to adjust prices, for example for rent or subscriptions.
Do you want to adjust your prices based on an index? Follow the steps below.
Statistics Netherlands (CBS) publishes several price indexes. Frequently used indexes are:
Choose the index that suits your business activity best. Use the same index for every price adjustment. That way your customers will know how you set your prices.
When you open the table of a CBS price index, you will see the base index figure by default. The CPI, PPI, and SPPI are about all products, wages, or services within that index. The overall CPI figure shows, for example, how much households in the Netherlands spent on products and services.
You can then filter within the price index by your spending category, service, or product. How you use the filters differs for each price index.
Combining price indexes
Do several different factors affect your prices? You can combine several price indexes for your calculation. See step 5 for a calculation example.
You can adjust your prices regularly, for example, monthly, quarterly or annually. Or less frequently, for example, once every 5 years. This is up to you.
Choose a fixed period and mention this in your contracts or general terms and conditions. This will make it clear to your customers when you adjust your prices.
Explain how you index your prices in your general terms and conditions or contracts.
For example:
- the name of the index and the reference year (for example: CPI, 2015 = 100)
- the moment of indexation
- how often you intend to adjust prices (monthly, quarterly or annually)
Read more about putting price changes in contracts (in Dutch).
Do not change existing price agreements
Do you have an existing agreement with a customer for the price of your product or service? Then you may only change the price if the general terms and conditions state you can.
Choose from these options:
Do you want to adjust your price every month, quarter or year?
Look in the price index of your choice for the price change compared to a month, quarter or year earlier.
Take this number as a guideline for your price adjustment.
Many entrepreneurs choose to adjust their prices annually. You do not have to calculate the price change yourself then. You can use the number in the table under 'annual change' (jaarmutatie).
How to calculate the price change: an example
You run a dry cleaning business and index your prices annually based on the CPI. In January 2025, the index was 120.7. In January 2026, you want to set your new prices. The CPI has risen to 126.0. You calculate the price increase as follows:
- New price index ÷ old price index × 100 - 100 = price change.
In this example, the price increase is: 126.0 ÷ 120.7 × 100 - 100 = 4.4%. This percentage is, when rounded, the same as the annual change.
Would you like to adjust your price less frequently, for example once every 5 years? Check the price index of your choice to see how the price index has developed since your last price change. Take this change as a guideline for your price increase or decrease.
Calculation example
You import pet food. You adjust your prices once every 5 years based on the PPI. The last time was in 2021. In January 2021, the PPI was 94.1. In January 2026, the PPI is 114.9.
You calculate the price increase as follows:
- New price index ÷ old price index × 100 - 100 = price change.
You increase your price (rounded) to 22,1% (114,9 ÷ 94,1 × 100 - 100).
You can also use more than one price index for your price adjustments . For example, because both staff wages and material prices determine your prices.
You then use a weighting per price index. You decide how important each price index is for your price.
For example, are you using 2 indexes with equal weighting? Then you weight both indexes by 0.5. If one index is more important than the other, you can also choose a different weighting distribution. For example:
- 0.75 for the price index that has the most affect on your prices
- 0.25 for the other index
The rule is that the weightings together always add up to 1.
Calculation
You have chosen to calculate your prices based on the CPI and DPI. Both price indexes have equal weight, so 0.5. The last time you indexed your prices was in January 2025. At that time, the CPI was 107.5 and the DPI was 107.2. In January 2026, you want to calculate your new prices. Then the CPI is 110.4 and the DPI is 109.3. The price adjustment is:
- ((weighting 1 x new price index 1) + (weighting 2 x new price index 2)) / ((weighting 1 x old price index 1) + (weighting 2 x old price index 2)) x 100 - 100.
This becomes: ((0.5 x 110.4) + (0.5 x 109.3)) / ((0.5 x 107.5) + (0.5 x 107.2)) x 100 - 100 = 2.3
You increase your prices by 2.3%
Before implementing your new prices, announce when the price adjustments will take effect. You can announce this in writing or online. If you want to adjust your prices regularly, always use the same index and period. This way you are clear to your customers.