The 40-category trap
New budget users tend to think more granularity equals better insight. They create separate categories for coffee, lunch, dinner, snacks, groceries, household supplies, cleaning, alcohol, restaurants, fast food, delivery, and tips. Within a week they're paralyzed at the supermarket trying to decide whether crackers count as snacks or groceries. Two weeks in, they abandon tracking entirely. The category list killed the habit.
The 8-12 category sweet spot
Real-world analysis shows that 8 to 12 top-level categories cover virtually all personal spending without ambiguity. A solid starter set:
- Food & Groceries — supermarkets, food shopping (not restaurants)
- Restaurants & Cafes — eating out, delivery, coffee shops
- Transport — public transit, taxis, fuel, parking, car maintenance
- Housing — rent, utilities, mortgage, repairs
- Health — pharmacy, doctors, insurance, gym
- Entertainment — subscriptions, movies, hobbies, books
- Shopping — clothes, electronics, gifts, household items
- Other — anything that doesn't fit above
When to split a category
After two or three months of tracking, look at where 'Other' or one large category dominates. If 'Shopping' eats 25% of your budget and you can't tell what's driving it, split it into 'Clothes' and 'Electronics & Gadgets'. The rule: only split when one category gets too big to read, not preemptively. Categories should reflect questions you actually want to answer.
System vs custom categories
Most apps offer a default set of system categories and let you create custom ones. Use system categories whenever possible — they're better designed for cross-app comparison and AI categorization. Create custom categories only for genuinely unique parts of your life — say, 'Music gear' if you're a musician, or 'Books' if you read a lot and want to track it separately. Resist the urge to recreate the entire system list with slightly different names.
Good categories answer real questions. Bad categories are a long list of tiny labels that explain nothing.