Reading Price Displays

Products on the same shelf are often displayed in ways that resist comparison.

Normalise the unit

"300 g", "100 g", "20 g × 15 sticks" — different units cannot be compared directly.

Convert to price per gram first.

price per gram = price ÷ weight in grams

Price per gram is still an intermediate step.

What matters is how much you use. Standard is 20 g per 150 ml water, 18 g per 150 ml milk.

cost per serving = price ÷ (weight ÷ per-serving amount)

300 g at ¥1,500 is 15 servings at 20 g, so ¥100 each.

"20 g × 15" totals 300 g and 15 servings. Same arithmetic.

Strength cannot be reduced to stretch the count, though.

Display conventions vary by retailer. Check which basis you are comparing on.

Product price alone misrepresents the cost.

300 g at ¥1,500 plus ¥500 shipping is effectively ¥2,000 — ¥133 per serving rather than ¥100.

Bundling for free shipping works only if the quantity fits inside the two-week-to-a-month post-opening window.

More weight at the same price lowers the per-gram cost.

Useless if you cannot finish it. Check that the additional amount fits your consumption window.

Two 300 g packages at the same price can be built very differently.

That does not appear in the price. The ingredient list, ordered by weight, is where it shows.

Not mandatory, so absence means nothing in particular.

Where present, it adds a data point. Uji, near Kyoto, is the historic centre of tencha production.