Computers & Laptops

RAM Upgrade Calculator

What an upgrade leaves you with, and how far it gets you towards a target.

5 inputs Free, no sign-up

Your figures

Only if a slot has to be freed for a larger module.

Try an example

Result

Your result

Enter your figures and the result appears here.

Estimates only. Rates, fees and specifications change. Confirm against the official source before you rely on a figure — see our disclaimer.

About this calculator

An upgrade is not always addition. If every slot is occupied, adding memory means taking something out first, and the machine ends up with less added than was bought.

Enter what is fitted, what is going in, what is coming out, and the target if you have one.

How to use this calculator

  1. Enter the memory currently fitted.
  2. Enter what you are adding.
  3. If a slot has to be freed, enter what is coming out.
  4. Set a target to see how far the upgrade gets you.

The formula

New total = Fitted now - removed + added
Shortfall = Target - New total
SymbolMeaningUnit
Fitted now Memory in the machine GiB
Added What is going in GiB
Removed What is coming out GiB

Worked example

8 GB fitted, 16 GB going in, aiming at 32 GB:

New total = 8 + 16 = 24 GB
Shortfall = 32 - 24 =  8 GB

Which is 75% of the way there.

Notes and limits

  • Nothing here checks compatibility. Slot count, the maximum the board and the processor support, the memory standard and the form factor are separate questions, and the answers are in your machine's manual.
  • Many laptops have memory soldered to the board and one free slot. Where that is the case the soldered part cannot be removed, and the ceiling is lower than the arithmetic suggests.
  • An unmatched pair can drop part of the range out of dual-channel operation, which costs a little performance even though the capacity is right.
  • To decide whether you need the upgrade at all, the RAM requirement calculator adds up what your own work uses.

What this calculation assumes

  • Arithmetic only. No claim is made about whether any machine will accept these modules.
  • Memory is counted in binary units, as it is sold.

Frequently asked questions

How much RAM will I have after upgrading?

What is fitted now, minus anything you have to remove, plus what you are adding. 8 GB with a 16 GB module added is 24 GB - unless a slot had to be freed, in which case it is less.

Do I have to remove the existing modules?

Only if the slots are full. A machine with two free slots takes the new modules alongside the old ones; a laptop with one slot occupied and none free means the old module comes out.

Can I mix different sizes?

Usually yes, and the capacity adds up normally. The cost is that part of the range may run in single channel rather than dual, which is a small performance difference rather than a fault.

Related calculators