Build a budget from your own baseline
Use observed household spending and an explicit adjustment instead of treating a national average as a personal target.
monthly budget = weekly baseline × 52 ÷ 12Research standards
Evergreen methods, clearly separated from changing data
Our core advice is built from transparent formulas and household inputs. Prices, benefits, fees and official statistics are treated as dated evidence—not permanent truths.
Compare usable cost, not package price
The durable comparison is price per common unit adjusted for the share you will actually use.
usable unit cost = price ÷ (quantity × usable share)Measure savings against a clean baseline
A saving is the difference between comparable baskets, not a coupon total or an advertised percentage.
savings rate = (baseline cost − new cost) ÷ baseline cost × 100Calculate cost per eaten serving
Recipe value depends on the servings actually eaten and the ingredients actually used.
cost per eaten serving = ingredient cost used ÷ servings eatenMeasure how much of the basket had a job
A useful list connects purchases to meals, staples or a deliberate reserve before checkout.
planned coverage = planned items ÷ total items × 100Track the value eaten, not only the value bought
Waste changes the true cost of every product, especially perishables and bulk packages.
waste-adjusted cost = purchase cost ÷ share consumedEvidence policy
What changes—and what does not
Evergreen: formulas, definitions, comparison frameworks, decision rules and step-by-step methods.
Monitored: government program limits, recall records, inflation indexes, membership fees, rewards terms and published benchmark studies.
Historical: an older figure may remain when it explains a trend or example, but it must be presented as a dated snapshot rather than a current promise.
We do not invent surveys, ratings, savings percentages or credentials. Derived examples must be reproducible from the inputs shown. A page is updated when its meaning or a monitored source changes—not merely to display a newer date.
Original research standard
Reproducible household models
Grocery Mentor's original analysis uses scenario modelling: the same formula is run across household sizes, usable quantities, servings, waste shares or shopping cycles. Assumptions are stated so another reader can reproduce the result. These models are educational planning tools, not a substitute for official eligibility, food-safety or financial advice.