How to Compare Grocery Prices Across Stores and Save
The best way to compare grocery prices across stores is to compare the total cost of the same cart, not individual items. Write one shopping list, price it at each store, adjust for package sizes using unit prices, and add the cost of any extra trip. The store with the lowest total is your cheapest — even if it is not the cheapest for every single item.
Here is a simple five-step method that works with any store and takes about 20 minutes the first time.
Why Item-by-Item Comparison Misleads You
Stores price strategically. A supermarket can advertise the cheapest milk and eggs in town and make it back on produce, cleaning products, and snacks. If you only compare the items you notice, you will pick the store with the best headline prices — not the best total.
The fix is to compare what you actually buy, as a whole basket.
Step 1: Build Your Standard Shopping List
Write down what you buy in a typical week or two: 20–40 items is enough. Use the same brands and sizes you normally buy, or note “store brand” where you are flexible. This list is your benchmark basket.
Step 2: Price the List at Each Store
Fill in the price of every item at each store you are considering. You can do it:
- In person, on your next trip.
- Online, using each store’s website or delivery app (in-store prices can differ slightly, so check a few items on your next visit).
- From the receipt of a recent trip.
A list app with prices makes this painless. In CartWise, you enter the price as you add each item and the app keeps a running total at the top of the list. Build the same list for each store and you get one total per store, side by side — no spreadsheet needed. (Here’s how the running total works.)
Step 3: Normalize With Unit Prices
When sizes differ, compare the unit price — per kilogram, liter, 100 grams, or per item. Most shelf labels print it in small type; otherwise divide the price by the quantity.
| Item | Store A | Store B | Unit price |
|---|---|---|---|
| Rice | 2 kg for $3.80 | 5 kg for $8.50 | A: $1.90/kg · B: $1.70/kg |
| Olive oil | 500 ml for $6.00 | 1 L for $11.00 | A: $12.00/L · B: $11.00/L |
The bigger pack only wins if you will finish it before it goes stale.
Step 4: Add the Hidden Costs and Discounts
Adjust each store’s total for:
- Loyalty prices and coupons you will genuinely use (not ones you need to remember to activate and never do).
- Travel — fuel, transit, or delivery fees, plus your time.
- Minimum order or membership fees for warehouse clubs and delivery services.
Step 5: Decide — One Store or a Smart Split
Now compare the adjusted totals:
- If one store wins by a clear margin, make it your main store.
- If the totals are close, pick the most convenient one — the savings will not survive extra trips.
- If a few items are much cheaper elsewhere (often meat, produce, or household goods), consider a planned second stop for just those items, on a route you already take.
Re-check every few months; prices and promotions shift.
Keep the Total Visible Every Week
Once you know where to shop, the goal is not to overspend there. A running cart total keeps you honest as you go: you see at item 12 that you are close to budget instead of finding out at the register. CartWise also keeps separate lists — your weekly shop, a party, a hardware run — each with its own total, and lets you share a list by QR code or WhatsApp so everyone in the household adds to the same cart.
Get CartWise free on Google Play →
Frequently Asked Questions
What is the best way to compare total grocery costs across multiple stores?
Price the same shopping list at each store and compare the cart totals, not individual items. Use unit prices (per kg, per liter, per 100 g) for items in different package sizes, include loyalty discounts you will actually use, and add the cost of extra travel before deciding where to shop.
Is it worth shopping at more than one grocery store?
Only when the savings beat the extra time and travel. A common approach is to do your main shop at the store with the cheapest total cart and make a second stop only for a few items with a large, consistent price difference.
How do I compare prices when package sizes are different?
Use the unit price — the price per kilogram, liter, 100 grams, or per item — which most shelf labels show. Divide the price by the quantity if the label does not. The lower unit price is the better deal, as long as you will use the whole package.
Is there an app that adds up my grocery total as I shop?
Yes. CartWise is a free Android grocery list app with a running price calculator: enter a price when you add an item and it keeps a live cart total, so you can compare one store’s total with another’s.