A calculator built for the aisle, not the spreadsheet
UnderBudget keeps your budget, your list, and your prices on one screen, so every item you add updates exactly where you stand.
No more adding up a cart in your head or switching between a calculator and a notes app. Set a limit, add items as you go, and watch your total and your room to spend update together, in real time.
No account. No setup. Your list stays on your device.
Total amount
₱615.00
₱2,385.00 remaining
21% used
Sound familiar
You start with a number in your head. Then the calculator app. Then a note with a running list. Then you lose track of which price you already added.
A few items in, you're recalculating from scratch because you swapped one thing for another. By the time you reach the register, you're just hoping the total comes in under what you meant to spend.
One screen, not three apps
UnderBudget puts your spending limit, your item list, and a fast entry keypad on the same screen. Add a name, punch in a price, set a quantity, and your total, your remaining balance, and your progress update immediately, before you move to the next item.
See the effect of every item the moment you add it, not at the register.
How it works
01
Enter the amount you have to work with before you start.
Everything after this is measured against a number you chose.
02
Name it, key in the price, adjust the quantity if you need more than one.
Your list builds itself as you go, no separate note required.
03
The total, what's left, and your percentage used shift the moment you tap Add.
You always know where you stand, not just at the end.
04
Edit a price, remove something, mark items as already in your cart.
You make the call while you can still change it.
A keypad that never leaves the screen
UnderBudget keeps a full number pad docked at the bottom of the screen the entire time you're adding items. Type a name, tap the price field, and the same keypad enters the price, then the quantity, without ever handing control to your phone's keyboard.
225
Price in, total updated, ready for the next item.
See where you stand, not just where you started
Your total spent, what's left, and your percentage used are always visible, not buried in a summary you have to tap into. As you get closer to your limit, the screen itself shifts, from a calm, comfortable tone to a warmer one as you approach the number you set.
You get the signal to slow down while you're still deciding, not after you've already paid.
Total amount
₱3,200.00
₱200.00 over budget
107% used
Comfortable, on track, or time to slow down. Always visible, never buried.
Everything else, in one screen
Distinguish what's in your cart from what's still on your list.
Glance down and know what you still need to grab.
Change a price, duplicate a repeat purchase, or undo a delete without starting over.
Swapped brands? Update the price in place.
Order items by when you added them, by price, or alphabetically.
Sort by price to see what's actually driving your total.
Clear your list for a new shopping trip without resetting the number you set.
Same weekly budget, new week's list.
Your list and budget are right where you left them next time you open the app.
Close the tab mid-shop, come back, nothing is lost.
Add it to your home screen and it works like any other app, including with a spotty signal.
Open it as fast as you'd open your calculator.
What actually changes
Built for a cart in one hand, a phone in the other
UnderBudget is designed to be used while you're actually shopping, not reviewed later at a desk. The keypad stays docked within thumb's reach. Buttons are sized for quick taps, not careful aim. The layout accounts for your phone's screen edges, so nothing important sits where your thumb already is.
It works in bright store lighting and dim ones, in light mode or a true dark mode. And because it installs like an app, opening it takes the same one tap as opening your calculator.
Beyond groceries
Groceries are where UnderBudget earns its keep, but the same screen works anywhere you're working against a fixed number.
Your list stays yours
UnderBudget doesn't ask for an account, an email, or a login. Your budget and your list are saved directly on your device, and they're there the next time you open the app.
Nothing you enter goes anywhere else. It's simply yours, on your phone.
Set a limit before your next shopping trip, and know exactly where you stand the whole way through it.
UnderBudget. Know what's left, while you still have time to change it.