This is the web site of Denis Defreyne, a software engineer living in Berlin.

Budget for replacing past purchases

One way in which budgeting reduces financial anxiety is by predicting expenses based on the expected lifetime of a purchase.

Limited-lifetime items with non-trivial cost

Some items have a limited lifetime (e.g. 4–5 years) and have a non-trivial cost (e.g. €1500). A non-trivial cost is a cost that, if it were to suddenly show up, would stir up my budget enough to cause stress. For me, these items fit primarily into three categories:

  • Electronic devices: laptop, phone, speakers, external display, …
  • Larger appliances: dishwasher, washing machine, …
  • Furniture with limited lifetime: office chair, mattress, …

This categorization isn’t all-encompassing: some items with non-trivial cost and limited lifetime don’t fit in properly (e.g. my glasses).

Note that this explicitly excludes items with non-trivial cost that have a long (expected) lifetime: my expensive (but gorgeous) kitchen table, for instance, which hopefully will last forever.

How to budget for replacement

To start, make a list of all items with limited lifetime and non-trivial cost (use the categorization above as a guideline). For each item, roughly estimate its remaining expected lifetime, and the cost to replace it. For example: I bought my MacBook Pro in late 2017 and expect its lifetime to be 5 years. At the time of writing (early 2021), the expected remaining lifetime is roughly 20 months, and replacing it would cost roughly €1500.

From now on, start budgeting each month the amount of money needed to cover the replacement cost in the expected lifetime. For example, the €1500 for replacing my MacBook Pro over the remaining 20 months of its lifetime comes down to €75/month.

For each future purchase with limited lifetime and non-trivial cost, do this budgeting calculation right when you make the purchase. For example, if I were to replace my MacBook Pro right now (assuming the replacement has the same cost of €1500 and the same expected lifetime of 5 years), I’d immediately start budgeting €1500 spread over 5 years, which comes down to €25/month.

Budgeting software exists to make this easier!

Lifetime vs. warranty

It is safe to use the warranty period as the lifetime, but this can be overly pessimistic. For example, my 2017 MacBook Pro is out of warranty, but I expect to keep on using it for at least another year.

In the end, it comes down to how much risk (uncertainty) you’re willing to take on.


I am able to deal with unanticipated expenses easily. Ideally, I only replace the item once I have all the money for replacement saved up, but even if I need to replace it before its expected lifetime ends, I will at least have a helpful part of the money saved up.

I am able to find out which items have extended past its expected lifetime. While this does not require me in any way to replace them, I can do so with no financial impact.

It makes me prefer purchasing long-lasting items over short-lasting ones, as short-lasting items will have a potentially higher monthly cost (for budgeting) associated with them.


It looks rather gloomy to immediately start budgeting for replacing an expensive item, right after purchasing it.