Budget Calculator
A personal budgeting tool that turns messy monthly numbers into a clear picture of where the money goes.
Project snapshot
- Starting at
- ₹4,000$60
- Delivery
- 3 days
- Status
- Live
- Tech stack
- React / Vanilla JS
< 1 min
Setup time
None
Sign-up
Export
3 days
Delivery
Overview
Budget Calculator is a lightweight, single-purpose web app for tracking income against expenses. A user enters what they earn and what they spend, groups spending into categories, and instantly sees whether they are saving or overspending — with a visual breakdown they can export and keep.
It is built for individuals and freelancers who want the clarity of a budgeting app without the overhead of signing up for a full finance platform. Everything runs in the browser, so there is no account to create and no data to trust to a third party.
The problem
Most people track budgets in a spreadsheet they forget to update, or in a heavyweight finance app that asks to connect their bank. Both fail for the same reason: too much friction. Budget Calculator removes it — open the page, type in the numbers, understand the situation in under a minute.
Who it's for
- Individuals who want a fast monthly budget without a subscription.
- Freelancers and contractors reconciling irregular income against fixed costs.
- Anyone who needs a shareable, printable budget summary (e.g. for a loan or visa application).
Features
Income vs. expense tracking
Add multiple income sources and expense line items; the running balance and savings rate update live as you type.
Category breakdown
Group spending into categories (housing, food, transport, etc.) and see what share of income each one consumes.
Visual charts
A donut chart for category share and a simple income-vs-expense bar, rendered client-side so they update instantly.
PDF export
Export the full budget — figures, categories, and charts — as a clean, printable PDF summary in one click.
Local persistence
The budget is saved to the browser's local storage, so returning to the page restores the last session without an account.
User stories
- As a salaried user, I want to enter my income and monthly bills so that I can see how much I have left to save.
- As a freelancer, I want to add several income sources so that I can budget around an irregular monthly total.
- As a user, I want to categorise my spending so that I can see which category is eating most of my income.
- As a user, I want to export my budget as a PDF so that I can print it or share it.
User flow
- 1
Enter income
The user adds one or more income sources with amounts; the total income headline updates live.
- 2
Add expenses
Each expense is entered as a line item with an amount and a category.
- 3
Review breakdown
Charts and the savings figure recompute on every change, showing surplus or deficit and category share.
- 4
Export & return
The user exports a PDF and/or closes the tab; local storage restores the budget on the next visit.
Architecture
A fully client-side single-page app — there is no backend. All state lives in the browser and calculations run on the client, which keeps hosting trivial (static files on any CDN) and running costs near zero.
State is a single budget object (income items, expense items, categories) held in React state and mirrored to local storage on change. Charts are derived from that object with pure selector functions, so the UI is a direct projection of state.
PDF export composes the on-screen summary into a print-friendly document generated in the browser, so no server round-trip or user data leaves the device.
Tech stack
Data model
Build plan
Day 1 — Core model & inputs
1 dayBudget data model, income/expense entry UI, live totals and savings calculation.
Day 2 — Categories & charts
1 dayCategory assignment, donut + bar charts, local-storage persistence.
Day 3 — Export & polish
1 dayPDF export, responsive layout, empty/edge states, and QA.
Deliverables
- Deployed, working Budget Calculator web app.
- Full source code with a README and setup instructions.
- Responsive UI for desktop and mobile.
- PDF export and local-storage persistence.
Integrations
- None required — the app is self-contained.
- Optional: analytics (e.g. privacy-friendly page analytics).
FAQ
Does it need an account or a database?
No. Everything runs in the browser and is saved locally, so there is nothing to sign up for and no server to run.
Can it handle multiple currencies?
It uses a single currency per budget by default; multi-currency can be added as a scope extension.
Is my financial data sent anywhere?
No. Figures never leave the device — calculations and PDF export both happen client-side.
Can it be branded for my business?
Yes. Colours, logo, and the exported PDF layout can all be customised as part of delivery.
Want Budget Calculator built for you?
Share your requirements and CodersArts Build will scope it into a fixed timeline and price, starting at ₹4,000.
Start this Project