Cash Stuffing & Sinking Funds Calculator
Enter your monthly income, name your own envelope categories with a monthly amount for each, and add sinking-fund goals with a target month to get an exact savings plan -- per-envelope dollars and cent-exact monthly set-asides for every fund. Nothing is collected, stored, or sent anywhere; every calculation happens right here in your browser.
Your numbers
Your plan
Envelopes
| Envelope | % of income | Monthly $ |
|---|---|---|
| Envelope total |
Sinking funds
No sinking funds added yet -- add one above to see the monthly savings math.
| Fund | Goal | Target month | Months left | This month |
|---|---|---|---|---|
| Sinking funds this month |
- Monthly income
- Envelope total
- Sinking funds (this month)
- Total allocated this month
- Remaining
How these numbers are calculated
Envelope amounts are whatever you type in -- this tool doesn't force them to add up to your income, it just shows each one's share of it and totals everything for you. Sinking-fund monthly amounts are goal ÷ months remaining, done in exact cents (never floating-point dollars), counting the target month itself as a savings month. Any leftover pennies from that division are added to the earliest months' deposits -- largest-remainder rounding, the same method this calculator's sibling tool (the Wedding Budget Calculator) uses for category dollars -- so the running total always lands on your exact goal by the target month, not a penny short or over.
Cash stuffing & sinking funds FAQ
What is cash stuffing?
Cash stuffing is a budgeting method where you withdraw your planned spending money on payday and physically divide it into labeled envelopes -- one per spending category. When an envelope is empty, spending in that category stops until the next payday, which makes overspending visible in a way a bank balance often isn't.
How many envelope categories should I start with?
Most people do better starting with 5-8 categories rather than trying to track everything at once -- fewer categories means less to manage on payday and less to reconcile at month end. You can always split a category later (like breaking Groceries into Groceries and Household Supplies) once you have a feel for where the money actually goes.
What is a sinking fund?
A sinking fund is money set aside gradually, a little each month, toward a specific future expense with a known or estimated cost -- car registration, holiday gifts, an annual insurance premium, a vacation. Instead of a surprise bill draining your checking account all at once, the cost is spread out and already saved by the time it's due.
How do I calculate my sinking fund's monthly savings amount?
Divide the total goal by the number of months between now and your target date: goal amount ÷ months remaining. This calculator does that math for you in exact cents, including the target month itself as a savings month, and it distributes any leftover pennies across the earliest months so your running total lands on your exact goal by the target month -- not a penny short or over.
What if my envelope totals add up to more than my income?
This calculator flags it directly -- the summary switches to an over-budget total showing exactly how much you're short. Common places to trim first are discretionary envelopes like Fun Money, Subscriptions, and Gifts before cutting into fixed obligations like Rent Reserve or Utilities Buffer.
Does cash stuffing work if I use a debit card instead of physical cash?
Yes -- many people replicate the envelope method digitally with separate savings sub-accounts or a budgeting app instead of physical cash, tracking the same category limits and sinking-fund goals without carrying bills around. DeskLark Studio's upcoming PocketFunds app is built for exactly that.
Want more than a calculator?
This tool covers the math. These two go further, if you want them.
Printable · $7 instant download · Coming soon
Cash Stuffing & Sinking Funds Savings System
The full 7-page system: cut-out envelope category labels, a sinking funds tracker for multiple goals across all 12 months, a 52-week savings challenge tracker, a monthly savings summary, and a quick-start guide. Print at home in US Letter or A4.
In the worksiOS app · Coming soon
PocketFunds
The envelope method and sinking funds, digital -- no cash to carry, same category limits and goal tracking as this calculator, right on your phone.
In the works