Expense Tracker
Summarises a pasted expense list by group and by concentration, and sorts subscriptions by what they cost a year rather than a month.
Expenses this month £881.59 across 13 lines
largest £178.00
smallest £3.20
average £67.81
middle one £62.50, which is the figure a typical line looks like
How concentrated it is
the largest fifth of lines 48.5%
the largest half 86.7%
which means a decision about the top few lines is worth more than a decision about all the rest
The largest lines
Train tickets £178.00, 20.2% of the total
Dentist £145.00, 16.4% of the total
Weekly shop £104.30, 11.8% of the total
Weekly shop £96.40, 10.9% of the total
Boots £89.99, 10.2% of the total
By group
food £361.10, 41% across 8 lines
transport £240.50, 27.3% across 2 lines
health £145.00, 16.4% across 1 line
clothes £89.99, 10.2% across 1 line
gifts £45.00, 5.1% across 1 line
If this repeats
frequency monthly, 12 times a year
a year £10,579.08
a month £881.59
Monthly subscriptions, by what they cost a year
Gym £38.00 a month is £456.00 a year
Phone £22.00 a month is £264.00 a year
Streaming £15.99 a month is £191.88 a year
Music £10.99 a month is £131.88 a year
Cloud storage £2.49 a month is £29.88 a year
total a year £1,073.64
which is the part of spending nobody decides on twice, and the reason a small monthly figure deserves an annual one next to it
Against income
income a month £2,400.00
these expenses 36.7%
subscriptions a month 3.7%
What a cut would be worth
5% off the total £44.08 a month, £528.95 a year
10% off the total £88.16 a month, £1,057.91 a year
20% off the total £176.32 a month, £2,115.82 a year
£881.59 across 13 lines, and the largest fifth of them holds 48.5% of
it. Spending is concentrated, so a summary that treats every line
equally hides where the money actually went.
The average and the middle line are close, at £67.81 and £62.50, which
means this list has no single line distorting it and the total is a fair
summary.
The subscriptions total £1,073.64 a year. Sorting them by annual cost
rather than monthly reverses how they feel: a small monthly line nobody
decides on twice outlasts a large one-off that felt expensive and was
over.
A month of expenses is a sample, not a pattern. One unusual purchase
moves the total more than a habit does, which is why three months tells
you something a single month cannot.
Categories are only as good as the discipline behind them. If half the
lines end up in one bucket called "other", the summary is arithmetic
rather than information.
Cutting the largest lines is unpopular and effective; cutting the
smallest is comfortable and pointless. Housing, transport and food are
usually the top three, and they are where a real change lives.
Nothing here is uploaded. The list stays in the browser, which matters
more for a bank export than for most things a calculator is given.
Output is valid and updates as you type.
Fix the highlighted fields to update the output.
Totals are the easy part of an expense list. The useful parts are the shape and the recurring lines.
Spending is concentrated. On the example the largest fifth of the lines carries 48.5 percent of the money and the largest half carries 86.7 percent, which means a decision about the top few lines is worth more than a decision about all the rest. A summary that treats every line equally hides that.
The other thing worth separating is recurring from one-off. A £15.99 subscription is £191.88 a year and reads as nothing on a list of purchases; a £145 dentist bill reads as alarming and is over. Sorting by annual cost reverses the order of most expense lists, and the subscriptions on the example come to £1,073.64 a year.
How to use
- Paste the expenses, one a line, as a label and an amount. A group after a pipe groups them.
- Say what period they cover and whether they repeat, to see the annual figure.
- List monthly subscriptions separately to see what they cost a year.
Example
Thirteen lines from a month, five subscriptions, against £2,400 of income:
Expenses this month £881.59 across 13 lines
largest £178.00
average £67.81
middle one £62.50, which is the figure a typical line looks like
How concentrated it is
the largest fifth of lines 48.5%
the largest half 86.7%
The largest lines
Train tickets £178.00, 20.2% of the total
Dentist £145.00, 16.4% of the total
By group
food £361.10, 41% across 8 lines
transport £240.50, 27.3% across 2 lines
Monthly subscriptions, by what they cost a year
Gym £38.00 a month is £456.00 a year
Phone £22.00 a month is £264.00 a year
Streaming £15.99 a month is £191.88 a year
total a year £1,073.64
Against income
these expenses 36.7%
subscriptions a month 3.7%Eight coffees and takeaways total less than one dentist appointment, which is the sort of thing a list sorted by size makes obvious and a category summary hides.
Pitfalls
The average is usually the wrong summary. When a few large lines pull it above the middle one, the average describes purchases rather than habits. The tool says so when the gap is large.
A month is a sample. One unusual purchase moves a month’s total more than a habit does. Three months tells you something a single month cannot.
Categories are only as good as the discipline. If half the lines end up in “other”, the summary is arithmetic rather than information.
Subscriptions are the spending nobody re-decides. They were agreed once and renew silently. The annual column is the one that prompts a decision.
Concentration is the reason to start at the top. Cutting the largest lines is unpopular and effective. Cutting the smallest is comfortable and pointless.
Business expenses need the tax treatment separately. This totals what was spent, not what is deductible, and the two differ by more than most people expect.
Bank exports are sensitive. Nothing here is uploaded, which is the reason to be careful with tools that are not this one.
Compatibility
Arithmetic in the browser: nothing is uploaded and nothing is stored.
Lines are parsed rather than entered one field at a time, so a spreadsheet or bank export pastes directly. The amount is the last number on a line, which lets a label carry digits, and a line with no number is skipped as a heading rather than counted as zero.
Concentration is the share of the total held by the largest fraction of lines, computed for a fifth and a half. The test suite pins the two cases with a known answer: an evenly spread list is exactly as concentrated as the share taken, and a list where one line holds everything is fully concentrated at any share.
The median is computed properly for an even number of lines, so the “middle one” figure is the average of the two middle values rather than an arbitrary side.
Frequently asked questions
What format should I paste?
Label amount, with an optional | group at the end. Colons, equals signs, currency symbols, thousands
separators and trailing comments after # all work. Headings without a number are skipped.