The buffer

Choose the balance you want to stay above and understand when Ebbe marks a month as tight.

The buffer turns the forecast into a clear answer: this is the month it gets tight. It is the balance you want to stay above and the only threshold Ebbe uses. There are no extra warning levels or percentages to configure.

What “tight” means

The buffer is the amount you want your balance to stay above.

Ebbe projects a closing balance for every month in the horizon. Any month whose closing balance falls below the buffer is marked: the row is tinted, the month carries a “below your buffer” badge, and the balance in the chart’s tooltip turns red. The headline figure at the top of the forecast names the first such month, and that is the whole answer the application exists to give.

The buffer is different from a savings goal or overdraft limit. A savings goal is an amount you want to reach; the buffer is an amount you do not want the projected balance to fall below.

The buffer is compared with the balance at the end of each month, not the lowest point within it. A month that dips on the second and recovers by the twenty-eighth is therefore not marked.

Choosing a number

The useful question is not “how much would I like to have” but “below what figure do I start moving things around?”

For most households that is somewhere between one month’s fixed costs and three. If the rent, the insurance and the standing orders come to €1,800, a buffer of €2,000 says: I want next month’s obligations covered before I count anything as spare.

The demo household uses €2,000 against an opening balance of about €2,800 — close enough that a single unexpected repair pushes it under, far enough that ordinary months are comfortable. That is roughly the shape a buffer should have. A buffer nothing ever crosses is not measuring anything; one that is crossed in every month is not a threshold, it is a description of your situation.

Zero is not a buffer

A new account starts with the buffer at zero. The forecast displays “No buffer set” until you choose a value.

Zero would mean: warn me when the account is empty. By then the warning has no use — the point of a forecast is the months of notice, and a threshold at the bottom of the range gives you the least possible amount of it. Any figure you would actually react to is better than zero, including a rough one.

A negative buffer is allowed, and it is not a mistake in the form. If you have an arranged overdraft you genuinely use, the line you care about is somewhere inside it, and Ebbe will take −€500 as readily as €2,000.

What it does not do

The buffer changes nothing about the projection. It is a line drawn across a picture that would look exactly the same without it: no figure is recalculated, nothing is set aside, no month is altered. Moving it moves only which months are marked.

One thing it quietly governs, which is worth knowing: while the forecast shows a month below the buffer, Ebbe will not ask you to support it. Asking somebody for five euros on the screen that has just told them their balance goes under in November is the worst moment there is.

Where to set it

Settings → Budget, the field marked Buffer. It belongs to the budget rather than to you, so everyone reading that budget sees the same line.

Next to it is Months ahead, which decides how far the projection runs — 12, 24, 36 or 60. The two work together: a buffer is only useful over a horizon long enough to contain the thing that will breach it. If you have a large payment eighteen months out, a twelve-month horizon will tell you everything is fine, and it will be right about the twelve months it looked at.