You probably think the big number on a family holiday is the flight or the room. It usually is not. It is the accumulation of small...

You probably think the big number on a family holiday is the flight or the room. It usually is not. It is the accumulation of small, unplanned spending once you are there: the second ice cream, the taxi you did not budget for, the gift shop at the end of every single attraction, the meal out you did not mean to have because everyone was tired and hungry at the same time. None of these show up when you price the trip in advance, which is exactly why they wreck the number you had in your head.
The fix is not a spreadsheet with forty rows. It is setting a daily spending number before you leave and treating it the same way you would treat a fuel budget: not aspirational, just true. If the daily number is honest, you stop making decisions on the fly, tired, in front of your kids, which is the worst possible time to make them.
Two categories deserve most of your planning attention because they are the two you can actually control: accommodation and food. Everything else, transport, entrance fees, incidentals, is smaller and more forgiving. Get those two right and the rest takes care of itself.
If you have a fixed amount to spend, the single highest-leverage decision is trading hotel polish for space and a kitchen. A self-catering place, even a modest one, does two things a hotel room cannot: it lets you eat two or three meals a day at a fraction of restaurant prices, and it gives kids somewhere to be bored, loud, or asleep without three other people in the room. Restaurant meals for a family add up fast, and they add up every single day of the trip, which makes them the biggest lever you have.
This does not mean cooking full meals on holiday. It means breakfast at the table instead of at a cafe, lunch assembled from a local shop instead of ordered from a menu, and one proper meal out as the treat rather than the default. That single swap, three meals down to one, is usually where the real savings live, and it is the one that has the smallest impact on how the holiday actually feels. Nobody remembers the good toast. They remember the beach, the walk, the game in the garden.
The second highest-leverage trade is time of year and length of stay, not distance from home. A week close by, timed around when things are quieter and cheaper, buys more actual holiday than a shorter trip somewhere further away that costs the same. Kids do not experience a holiday in miles travelled. They experience it in unstructured time: the second and third day, once everyone has stopped adjusting and started relaxing, is usually when it starts paying off. A shorter trip skips straight past that day.
Feeling like a proper break has less to do with money than most people assume. It comes from three things: a change of routine, at least one full day with nothing scheduled, and everyone, including you, getting to do something they specifically chose. A day with no plan, where the only rule is that nobody is rushing anywhere, does more for how a holiday is remembered than an extra paid activity does.
If you are cutting cost, cut it from the things that are interchangeable, not the things that are not. A themed attraction with an entry fee is interchangeable with a free outdoor space if the aim is a good day out. Time with no agenda is not interchangeable with anything. Protect that first and let the paid extras be the part you trim.
Once you have kids on the trip, time with your partner does not disappear, it just has to be built rather than assumed. A few ways to do that without paying for a sitter:
None of this requires paid childcare or extra spending. It requires deciding in advance that this time matters as much as the kids' time does, because on most family trips it is the first thing that gets sacrificed when the schedule gets tight.
Before you book anything else, work out your daily spending number and write it down somewhere you will actually see it during the trip, not just in a planning document you forget by day two. Then decide, in advance, which one thing on the trip belongs to you and your partner alone. Put both of those in place before you look at accommodation, and the rest of the planning gets easier because the two decisions that cause the most stress, money and time, are already made.