It's easy to assume you'll need a similar income in retirement as during your working life to maintain your lifestyle. However, many people find they spend less when they stop working.
We’re not able to provide exact figures on how much income you’ll need, but this article from Pensions UK may be helpful for your retirement planning.
The guidelines in the article assume that you’ll reduce some of your expenses (like your mortgage payments and childcare), so the remaining income is similar to what you’re used to living on.