Power BI and DAX, with the numbers checked

Each guide builds one real report against one real dataset. The DAX is written out in full. The dataset downloads with the guide. The numbers the guide says the measures return were computed independently before publication. If a number cannot be checked, the guide does not ship.

Latest guides

GUIDE 06 · DAX · DATE TABLE

Build a Power BI date table in DAX: CALENDAR and ADDCOLUMNS, with no gaps

731 rows from 1 January 2024 to 31 December 2025, no gaps. February 2024 has 29 days; February 2025 has 28.

GUIDE 05 · DAX · SHARE OF TOTAL

Power BI category share of total in DAX: one DIVIDE measure, no helper column

Desks takes 46.4% of January–October 2025 revenue; Chairs 33.8%, Lamps 19.8%. One measure, no helper column.

GUIDE 04 · DAX · YEAR-TO-DATE

Power BI year-to-date sales in DAX: TOTALYTD and YTD versus last year

Year to date through October 2025: $122,707 against $96,456 a year earlier, +27.2%. The total resets every 1 January.

GUIDE 03 · DAX · MONTH-OVER-MONTH + MOVING AVERAGE

Power BI month-over-month change and a 3-month moving average in DAX

October 2025: $13,436 against $13,415 in September, +0.16%. The 3-month moving average is $13,377, the highest in the data.

GUIDE 01 · DAX · TIME INTELLIGENCE

Power BI year-over-year sales: a DAX measure that returns the right prior-year number

Three measures — Total Sales, Sales PY, YoY % Change — on a calendar table. October 2025 comes out at $13,436 against $10,995 a year earlier: +22.2%.

GUIDE 02 · DAX · RUNNING TOTAL + RANK

Power BI running total and category rank in DAX, with no helper columns

One CALCULATE measure for the running total, one RANKX measure for the category rank. The 2025 running total reaches $122,707 by October; Desks ranks first.

How a guide is checked

Every guide names the software it was verified with and the exact results the measures must return. The measure results are computed a second way — the same aggregations run in Python against the same CSV — and the guide only publishes when the two agree to the cent. The Method page states how every guide is checked.