Methodology and Trust
How PricePer calculates useful value for protein powder and coffee beans, how freshness works, and what confidence labels mean.
What PricePer compares
Protein Powder
PricePer compares protein powder by $/g protein and g protein per dollar. The goal is to compare the useful protein you get from a tub or bag, not just the sticker price.
Open Protein Powder Value IndexCoffee Beans
PricePer compares coffee beans by $/100g and an estimated $/cup. The cup estimate is a practical guide, not a claim that every cup is brewed the same way.
Open Coffee Beans Value IndexProtein powder formula
For protein powder, PricePer needs the package size, serving size, protein per serving, and current price. Those facts usually come from the product label and the retailer listing.
Formula
Estimated total protein = package size / serving size x protein per serving
Price per gram of protein = current price / estimated total protein
Protein grams per dollar = estimated total protein / current price
Simple example
A 1,000g bag has a 30g serving size and 24g protein per serving.
Estimated total protein: 1,000 / 30 x 24 = about 800g protein.
If the bag costs $40, then $40 / 800g = $0.050/g protein, and 800g / $40 = 20g protein per $1.
Coffee beans formula
For coffee beans, PricePer needs the bag size and current Canadian price. The main comparison is $/100g because bag sizes vary a lot across grocery, warehouse, Amazon, and roaster listings.
Formula
Price per 100g = current price / bag size in grams x 100
Estimated cups = bag size in grams / grams per cup
Estimated price per cup = current price / estimated cups
PricePer uses 15g/cup as the standard default. Some people brew lighter cups and some brew stronger cups, so the Coffee Beans Value Index lets users change the cup strength assumption.
Example: a 1,000g bag at $25 is $2.50/100g. At 15g per cup, it makes about 66 cups, or roughly $0.38/cup.
Price freshness
Every offer card shows when PricePer last checked the price, such as "Checked today," "Checked 3h ago," or "Last checked 4 days ago - confirm before buying."
Retailer prices can change because of sales, coupons, subscriptions, regional pricing, flyer dates, stock changes, shipping to Canada, or membership rules.
Stale prices may still be shown for context, but they are visually downgraded and should not be treated as the best current deal without confirmation.
Source confidence
- Verified
- Price, package size, and key label facts were manually checked.
- High
- Structured data parsed cleanly and matches the expected product.
- Medium
- The price looks clean, but some product, package, or label details still need review.
- Low
- Extraction is uncertain or came from messy page text.
- Stale
- The price is older than the freshness threshold for that ranking.
- Local may vary
- Store, city, postal-code, or flyer pricing may differ.
- Shipping excluded
- The ranking uses shelf price and does not include shipping.
- Membership required
- The price may require Costco, club, or retailer membership.
Shipping and membership
Shelf price means the product price before shipping. It is useful for quick comparison, but it may not be your final checkout total.
Shipped price includes shipping to Canada only when PricePer has enough evidence to include or estimate it. If shipping is unknown, the page should say so clearly.
Free shipping can depend on cart size. A product may have a good unit price only if your cart reaches the retailer's free-shipping threshold.
Costco and other member prices are not hidden, because they can be useful, but they should be labelled when membership is required or local store pricing may vary.
How users can help
PricePer gets better when Canadian shoppers report useful price and product evidence. Found a better price? Report it.
- Report a wrong or stale price.
- Submit a product URL from a supplement store, roaster, grocery store, warehouse club, Amazon, Walmart, or another Canadian retailer.
- Report a better local, pickup, flyer, or member price.