Office PC spec calculator

"4 GB of RAM" in Office's requirements is for one program

Microsoft's official system requirements for Microsoft 365 are a 1.6 GHz 2-core CPU, 4 GB of RAM, 4 GB of disk space and DirectX 9 graphics. Windows 11 also lists 4 GB of RAM and 64 GB of storage as its minimum. Add the two and you get 8 GB of RAM, which is where this calculator starts.

What slows an office PC down is rarely one spreadsheet. It is three spreadsheets, two Word files, a chat app and ten browser tabs all open at the same time. Official requirements describe the floor for one program, and say nothing about how many you run together. So instead of asking which programs you use, this calculator asks how many windows you keep open.

In office work, memory runs out first

Every open window holds on to some memory until you close it, so the total keeps growing as windows pile up. When memory runs short, Windows starts borrowing space on the drive, which is far slower, and switching windows begins to stutter. That is the usual reason an office PC feels quick in the morning and sluggish by the afternoon.

The CPU is a different story. While you edit documents it is idle most of the time, and every CPU on sale today clears the official 1.6 GHz 2-core minimum. The exception is recalculating very large spreadsheets or building pivot tables, where more cores can shorten the wait, so the calculator suggests 6 cores or more in that case. That step is our judgement, not an official figure, and the result says so.

How the three answers turn into RAM

The floor is 8 GB. Keeping 4 or more windows open moves it to 16 GB. Keeping 10 or more open while mixing documents and the web adds another step, to 32 GB. Huge spreadsheets or image-heavy slides add a step, and video calls alongside documents keep it at 16 GB or more. We stop at 32 GB: beyond that the work is no longer typical office work, and measuring beats guessing from questions.

Measure with one number from Task Manager

If you are replacing a PC, open your usual files and tabs, then press Ctrl + Shift + Esc. In Task Manager choose Performance, thenMemory, and type the In use figure into "More precise". We add your headroom and round up to a size you can actually buy. For a PC you will keep for years, 30% headroom is a sensible default, since programs grow a little heavier with each version.

If you also enter the total shown at the top right and your PC is more than 85% full, Windows is already compressing memory and pushing it to the drive, so "In use" reads lower than what you really need. We cannot tell how much more from that PC, so we answer with at least the next size above what you have now.

No graphics card needed — just watch for the "F"

Office asks for DirectX 9, and Intel's official specifications (ARK) list DirectX 12 support for the integrated graphics on current Intel CPUs, which is plenty for documents, browsing and video. One thing to check: Intel CPUs whose name ends in F (such as the i5-14400F) have no integrated graphics at all, so a PC built around one shows nothing on screen without a separate graphics card.

To check a real PC against these numbers, enter its parts in the spec checker. If it will also play games or edit photos, pick those in the spec builder instead.