Your cushion: what it is and why it changes every day
The cushion is the least your checking and savings should hold today, so a purchase doesn't leave you short before payday.
Published Oct 29, 2026 · Checked against the app Oct 29, 2026 · 3 min read
When you ask Buyancy whether you can afford something, it needs a line to judge the answer against. That line is your cushion.
Your cushion is the least your checking and savings should hold on a given day, so that a purchase does not leave you short before your next payday.
What it is made of
It has two parts.
- Your minimum balance. The amount you never want your checking and savings to go under. You set it yourself. If you have not set one, it is $0.
- Everyday spending until payday. The everyday things that are not bills, like groceries and coffee, for each day until your next payday.
Add them together and you have your cushion for today.
Your minimum balance is $500 and you spend about $130 a day.
- 8 days before payday: $500 + 8 × $130 = $1,540.
- 1 day before payday: $500 + 1 × $130 = $630.
Why it changes every day
The closer you are to payday, the fewer days of spending you need to cover. So your cushion is smaller the day before payday than it was a week earlier.
Buyancy works this out for each day it looks at, not once for the whole answer. A purchase that fits comfortably after payday can still fall short the day before it, and the answer will tell you which day.
Where the spending figure comes from
There are two ways.
- You set it. Open the cushion in the header and choose "Everyday spending". You enter what you spend in a month, beyond bills and card payments. Buyancy uses a thirtieth of it for each day.
- We estimate it. If you have not set one, Buyancy reads your recent transactions and counts what you spend on everyday things, leaving out transfers, card payments and your recurring bills. It needs about a month of history to do this.
What the answer means
Every answer is one of three states, and each is judged against your cushion and your minimum balance.
- Yes. Your balance stays above your cushion every day Buyancy looked at.
- Wait. It stays above your minimum balance (or $0) but dips below your cushion on at least one day. The answer says which day, and how short you would be.
- No. It goes under your minimum balance, or under $0 if you have not set one.
A dip that was already coming before your purchase is not blamed on the purchase. The answer shows it separately, with what you could do about it.
What about credit cards?
Cards are not part of the cushion. Buyancy already takes each card's payment out of your checking on the day it is due, so adding the card balance to the cushion as well would count the same money twice.
If you share Buyancy with a partner
When you ask as a household, the cushion adds both of your minimum balances and both of your everyday spending figures. It uses whichever payday comes sooner. If one of you has not set a spending figure, the answer says so, and the cushion is lower than it should be.
Where to change it
Open the Cushion figure at the top of any page. You will find your minimum balance and your everyday spending there. Changes apply to your next answer.
This explains how Buyancy works. It is not financial advice, and it does not know your whole situation.