How Zado counts your money

This part is for anyone who wants every step: an accountant, a lawyer, a careful customer, or Penny when you ask her "exactly how did you get that?". Every number below can be checked by hand. The worked examples at the end are also checked by Zado's own code: if this page and the app ever disagree, a test fails and the change cannot ship.

The words

The formulas

Per envelope:

• in it = funded − spent
• still coming = max(planned − funded, 0)
• spent before funded = max(spent − funded, 0)
• set aside = max(in it, 0)

Per person, three questions, each with one answer:

1. Right now. Is everything set aside actually in checking? Covered when checking ≥ Σ set aside.
2. Before the next payday ("what can wait?"). Free before payday = checking − Σ set aside − bills due by the next payday that their own envelope doesn't hold − card promises. Covered when free before payday ≥ 0. "By" includes payday itself, because a paycheck can land after a bill does. An envelope's money pays its own bills first, soonest due first.
3. This month. Does the plan fit the pay? Covered when projected + carried in + brought forward ≥ Σ planned. Brought forward is money in checking, beyond the pay recorded this month, that "Start with what you have" gave a job: usually money from before the month (a paycheck on the 30th), but a refund, interest or a transfer in this month counts too. Zado says it is "already in checking", never when it arrived.

A card promise is money you already spent on a credit card from a funded envelope: it still has to leave checking when the card is paid, so it is held for the card.

What always holds

These identities are checked by code for every example below and for every synthetic payer in Zado's tests:

• I1. Σ funded ≤ arrived + carried in + brought forward. Nothing is funded with money that hasn't arrived.
• I2. For every envelope, funded − spent = set aside − spent before funded. In it is never rounded away.
• I3. "Short right now" happens exactly when checking < Σ set aside.
• I4. Money moved to your own savings account is never counted both there and as set aside in checking.
• Moving money between envelopes never changes Σ funded.
• Projected money is never spendable. It answers one question, whether the month's plan is realistic. The envelope tiles, "right now" and "before the next payday" use only money that has arrived.

What Zado never does

• Spend a paycheck that hasn't landed, or count a plan as money.
• Hide a negative. Spent before funded is shown, in amber, with what's still coming.
• Count a transfer between your own accounts as spending.
• Guess income with no rhythm. With no rhythm there is no projection, and Zado says so.
• Count interest, refunds or transfers in as pay. Only the paychecks from your pay schedule are projected.

Worked examples

Every example is the same story twice: in words, then as the exact inputs and results a test recomputes. All names and figures are invented.

The doctor

You planned $400 for the doctor this month. One $100 share of a paycheck went in. Then the bill came: $150. The envelope reads −$50 in it, $300 still coming: $50 was paid from elsewhere in checking before a paycheck covered it. Nothing is hidden, and nothing is due before payday, so nothing has to wait.

A weekly earner on the 8th

Paid $640 every Wednesday. On October 8 one paycheck has landed and three are still coming. The month's plan is $2,500, and no paycheck has been given a job yet. Checking holds $800. Nothing is due before the next paycheck on October 14, so nothing has to wait, and four weekly paychecks ($2,560) cover the $2,500 plan. Counting the whole month's plan against the money here on the 8th would have said "$1,350 short". That was the mistake this way of counting exists to stop.

The same weekly earner, after the paycheck gets its jobs

The October 7 paycheck is given to Bills ($640). Bills now reads $640 in it, $60 still coming. Checking still holds $800, but $640 of it has a job, so $160 is free before payday.

A late paycheck

The weekly paycheck expected on October 7 hasn't arrived by October 9. It is late, not missing (it is within 3 days), so it is still counted in the month and named. A $140 car insurance bill with no envelope is due on the 12th. Checking holds $150, so the bill is covered with $10 free, and everything else waits for payday.

A missing paycheck

Paid weekly from October 2. The October 9 paycheck still hasn't arrived on October 13, four days late. It is missing: not counted, and named. Without it, the pay expected this month is $2,600 against a $2,800 plan.

A 5-paycheck month

October 2026 has five Fridays. Paid $650 weekly from Friday October 2, so the month's pay is about $3,250, not the $2,600 a "four paychecks a month" rule would assume. Rent has $500 in it so far, with $900 still coming.

A bill due before payday that the free money doesn't cover

Paid on the 1st and the 15th. On October 9 a $220 phone bill with no envelope is due on the 12th. Checking holds $300, and $150 of it is Groceries money already set aside. The phone bill is $70 more than the free money. Only that bill is the problem: everything not due before the 15th can wait.

Pay with no rhythm

Gig income: two deposits this month, on no schedule. Zado won't guess the month's pay or the next payday, and says so. What's in Groceries is still exact: $180.

Edge cases

• Carry-over. When an envelope's carry-over switch is on, last month's leftover (its set aside at the end of the month) comes into the new month as funded. It arrived in an earlier month and kept its job. With the switch off, the leftover goes back to free money. A negative never carries: checking already paid it.
• A paycheck on the 30th. It arrived in September, so it is not October's pay. When you give it October jobs ("Start with what you have"), it is brought forward into October and counted in October's answer. Until then it is money with no job yet: free, and spendable, but not counted as October's pay.
• A refund in the same month. Money in checking that isn't recorded pay could be from September or could be a refund, interest or a transfer that landed in October. Zado can't always tell, so when Start gives it a job it is counted the same way and described only as "already in checking", never as money from before.
• A bill paid around the same day each month. Zado reads the days you actually paid it, from the bill's own account and near its amount, and expects it in that window: "around the 12th (8th–12th)". This month's payment counts as due from the day the window opens until it posts. Up to 3 days after the window it is late and still counted; after that Zado moves on to next month's. A charge to the same company from a different account, or for a very different amount, is not this bill's payment.
• A bonus. Money above the projection has no job until you give it one. It is free money.
• Two earners. Zado projects from one payer today: the one your pay schedule follows. A second earner's paychecks still count as arrived when they land.
• Credit cards. Spending on a card from a funded envelope is held for the card's payment, so it is counted once, not twice.
• Months before this way of counting began. They are history and are not rewritten. Their numbers stay what they were.

This is a way of counting your own money. It is not financial, investment or tax advice.