S/4HANA HANA Memory Sizing Estimator
Memory is the largest hardware line item in a move to HANA, and early budgets are usually guessed. This estimator walks from your current database size to a memory and disk figure in a few transparent steps so you can challenge the assumptions.
Your numbers
Used space in the current database including indexes, from the DBA, not allocated storage.
Row-store databases carry many secondary indexes that HANA does not need in the same way.
Data archived or deleted before conversion.
Column-store compression varies by data; treat 3 to 5 as a planning range and confirm with the sizing report.
From your own history of table growth.
Your results
Rough estimate for budgeting only. Use SAP sizing reports for your release and a certified hardware or cloud sizing for purchasing decisions.
Suggested memory vs compression factor
Sweeps Expected compression factor from 2 to 8, holding your other inputs fixed.
Sizing assumptions review
Optional: share your assumptions and we will flag the ones that usually move the budget the most.
Optional. The tool and every export work without this. No spam.
How to use it
Start with used database size from your DBA and estimate how much of it is index and free space. Add the share you expect to remove through archiving, then choose a compression factor. Set your measured annual growth and a planning horizon. The tool outputs compressed data today, at the horizon, and a suggested memory, data volume and log volume. Try different compression factors in the chart to see how sensitive the budget is.
- Use used space, not allocated tablespace
- Be conservative with the archiving percentage
- Run the official sizing report on the source system
- Re-run after the first test migration
The method
Net data is source size minus the index and free share. Archiving reduces it further. Dividing by the compression factor gives the in-memory footprint, which is then grown by compound annual growth over the horizon. A common planning rule keeps roughly half of memory for data and half for working space such as temporary query results and delta merges, so suggested memory is twice the future data footprint. Persistent volumes follow similar planning rules. These are budget rules, not a substitute for SAP sizing guidance.
Common mistakes
People forget that S/4HANA can change the data model, so some tables grow while others shrink, and they size from allocated storage rather than used. Another mistake is assuming the best compression result seen in a demo. Also remember that non-production systems, high availability and disaster recovery multiply the hardware or cloud cost. If you buy through a hosted or RISE offering, the provider sizes in set tiers, so check which tier your figure lands in.
Frequently Asked Questions
Is this a replacement for SAP sizing?
No. It is a budgeting estimate that exposes your assumptions. For purchasing, run the SAP sizing reports on the source system and use certified hardware or cloud sizing for the target release.
Why is suggested memory twice the data?
HANA needs working memory beyond stored data for queries, delta merges and temporary results. A planning rule of roughly half for data and half for working space is common, and your vendor may use a different ratio.
What compression factor is realistic?
It depends on your data. Many teams plan with 3 to 5 for a database moving from a row store. Treat anything higher as an upside until a test migration confirms it.
Does archiving really help that much?
Often yes, because old documents and change records can be a large share of the database. The benefit depends on retention rules and how much your auditors require to stay online.
Netray can help build a private assistant over your sizing reports and project documents so your Basis and finance teams get consistent answers.
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