Budget Builder Skill
Most budgets fail because they're aspirational fiction. This skill builds a realistic monthly budget from
someone's actual income and spending — categorized, with a clear surplus-or-shortfall number and a couple of
specific moves to fix the gap. It's an educational planning aid, not personalized financial advice.
Required Inputs
Ask for these only if they aren't already provided:
- Monthly take-home income (after tax), and whether it's steady or variable.
- Fixed costs — rent/mortgage, utilities, insurance, loan/debt minimums, subscriptions.
- Variable spending — groceries, transport, eating out, fun, shopping (estimates are fine).
- Goals & obligations — emergency fund, debt payoff, saving for something, dependents.
If numbers are rough, work with ranges and say so.
Output Format
Monthly budget — [name/household]
Income (take-home): $X
| Category |
Type |
Amount |
% of income |
| Housing |
Need |
$ |
% |
| Utilities & bills |
Need |
$ |
% |
| Groceries |
Need |
$ |
% |
| Transport |
Need |
$ |
% |
| Debt minimums |
Need |
$ |
% |
| Dining / fun |
Want |
$ |
% |
| Subscriptions |
Want |
$ |
% |
| Savings / goals |
Save |
$ |
% |
| Total |
|
$ |
100% |
Needs / Wants / Savings split: X% / Y% / Z% — with a one-line read vs. a 50/30/20 guideline (a reference point, not a rule).
Bottom line: surplus of $X (allocate it) or shortfall of $X (must cut/earn).
Top 3 moves — the specific, highest-impact changes (e.g. "renegotiate the $X subscription stack", "cap dining at $Y", "auto-transfer $Z on payday").
Notes — assumptions, and for variable income, budget against a conservative (low) month.
Quality Checks
Anti-Patterns
Based On
Personal budgeting practice (zero-based budgeting + the 50/30/20 needs/wants/savings guideline).
1---2name: budget-builder3description: Build a realistic personal monthly budget from someone's income and expenses. Use when asked to make a budget, plan monthly spending, allocate income, or get finances under control. Produces a categorized budget (a 50/30/20-style allocation tuned to their reality), a surplus/shortfall number, and concrete next moves. Educational, not regulated financial advice.4---5
6# Budget Builder Skill
7
8Most budgets fail because they're aspirational fiction. This skill builds a **realistic** monthly budget from
9someone's actual income and spending — categorized, with a clear surplus-or-shortfall number and a couple of
10specific moves to fix the gap. It's an educational planning aid, not personalized financial advice.
11
12## Required Inputs
13
14Ask for these only if they aren't already provided:
15
16- **Monthly take-home income** (after tax), and whether it's steady or variable.
17- **Fixed costs** — rent/mortgage, utilities, insurance, loan/debt minimums, subscriptions.
18- **Variable spending** — groceries, transport, eating out, fun, shopping (estimates are fine).
19- **Goals & obligations** — emergency fund, debt payoff, saving for something, dependents.
20
21If numbers are rough, work with ranges and say so.
22
23## Output Format
24
25### Monthly budget — [name/household]
26
27**Income (take-home):** $X
28
29| Category | Type | Amount | % of income |
30|---|---|---|---|
31| Housing | Need | $ | % |
32| Utilities & bills | Need | $ | % |
33| Groceries | Need | $ | % |
34| Transport | Need | $ | % |
35| Debt minimums | Need | $ | % |
36| Dining / fun | Want | $ | % |
37| Subscriptions | Want | $ | % |
38| Savings / goals | Save | $ | % |
39| **Total** | | **$** | **100%** |
40
41**Needs / Wants / Savings split:** X% / Y% / Z% — with a one-line read vs. a 50/30/20 guideline (a reference point, not a rule).
42
43**Bottom line:** **surplus of $X** (allocate it) or **shortfall of $X** (must cut/earn).
44
45**Top 3 moves** — the specific, highest-impact changes (e.g. "renegotiate the $X subscription stack", "cap dining at $Y", "auto-transfer $Z on payday").
46
47**Notes** — assumptions, and for variable income, budget against a conservative (low) month.
48
49## Quality Checks
50
51- [ ] Every dollar is assigned (expenses + savings = income; surplus/shortfall is explicit)
52- [ ] Categories are split into needs / wants / savings, with percentages
53- [ ] The plan is realistic for their actual spending — not an aspirational fantasy
54- [ ] Variable income is handled conservatively (budget the low month)
55- [ ] The top moves are specific and quantified, not "spend less"
56
57## Anti-Patterns
58
59- [ ] Do not present a budget that doesn't balance to income — name the surplus or shortfall
60- [ ] Do not set unrealistic cuts that won't survive week one — anchor to their real numbers
61- [ ] Do not ignore irregular costs (annual insurance, holidays) — prorate them monthly
62- [ ] Do not give generic advice — every recommendation should reference their figures
63- [ ] Do not present this as personalized financial advice — it's an educational plan to adapt
64
65## Based On
66
67Personal budgeting practice (zero-based budgeting + the 50/30/20 needs/wants/savings guideline).
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