Guides
Short and practical: what breaks, why, and the markup that doesn't.
Every spreadsheet, every template, or the whole catalogue. One payment, no subscription, a year of updates.
Add days to a date in Excel: days, weeks, months, working days
Add days to a date in Excel and Google Sheets: plain addition for days and weeks, EDATE for months and years, WORKDAY to skip weekends, due dates from payment terms — and why A2 + 30 drifts.
Excel date formulas: add days to a date, days between, date ranges, start and end of month
Date formulas for Excel and Google Sheets: adding days, weeks and months to a date, days between two dates, a date range test, month edges, age and weekdays — plus the two silent date mistakes.
Conditional formatting with a formula: highlight the row, past-due dates, blanks, duplicates, weekends
Conditional formatting based on another cell, in Excel and Google Sheets: $ anchoring, whole-row highlights, past-due dates, blanks, duplicates — and copying or removing a rule.
COUNTIF and COUNTIFS: not blank, multiple criteria, not equal, dates, wildcards
COUNTIF and COUNTIFS in Excel and Google Sheets: criteria syntax, non-blank cells, several conditions, not-equal, date ranges, wildcards, running counts.
Gantt chart in Excel without add-ins: conditional formatting, step by step
Draw a Gantt chart in Excel or Google Sheets with three conditional-formatting rules — no add-ins, no shapes, no macros. Progress fill, blocked bars, today.
Hours between two times in Excel and Google Sheets: night shifts, breaks, overtime
Hours worked from a start and end time: the ×24 rule, MOD for shifts past midnight, subtracting a break, daily and weekly overtime, rounding, [h]:mm.
Yes/No drop-down in Google Sheets: list, checkbox, COUNTIF
Make a Yes/No drop-down in Google Sheets with data validation, colour the answers, swap it for a checkbox, and count the Yeses with COUNTIF.
Loan amortization in Excel: PMT, month-by-month interest, and extra payments
Loan amortization schedule in Excel or Google Sheets: the PMT formula, interest from the balance each month, a schedule that stops at zero, extra payments.
Expense tracker in Google Sheets: the one SUMIFS you need, explained
Build an expense tracker in Google Sheets or Excel from a plain log: one SUMIFS by category and month, limits, data bars, and a twelve-month view.
Responsive email without a framework
Media queries are ignored by some of the biggest email clients. Fluid tables, max-width caps and Outlook ghost tables give you one layout that adapts everywhere, with no framework.
How to make a drop-down list in Excel and Google Sheets: yes/no, dependent, and how to remove one
Data validation in Excel and Google Sheets: a typed list, a range, a yes/no or ✓ cell, dependent lists with INDIRECT, and how to copy or remove one.
Excel templates without macros: how to build a spreadsheet you can audit
How to build an Excel or Google Sheets template without macros: named ranges, dropdowns, bounded ranges, conditional formatting, and formulas you can audit.
SUMIFS with multiple criteria: date ranges, another sheet, wildcards, OR — and why it returns 0
SUMIF vs SUMIFS: multiple criteria, date ranges, greater-than a cell, not equal, wildcards, another sheet, visible rows only — and why it returns 0.
Anatomy of a newsletter email
The blocks a newsletter is made of, in order: preheader, masthead, lead story, story list, one call to action, footer. What each one is for, how wide it should be, and what the law requires.
An Excel dashboard without pivot tables: SUMIFS, a summary sheet, and bars
A dashboard in Excel or Google Sheets that updates itself: a log sheet, a summary of SUMIFS and COUNTIFS, data bars and a chart — no pivot tables, no macros.
Find, highlight and count duplicates in Excel and Google Sheets with a formula
COUNTIF to flag duplicates, a conditional-formatting rule to colour them, marking only the repeats, counting distinct values, two-column keys, and the traps.
A chart that updates itself: line and bar charts in Excel and Google Sheets from a log
A chart in Excel or Google Sheets that stays right as you add data: a summary table it reads from, SUMIFS by month, a fixed range, empty months hidden.
VLOOKUP, INDEX/MATCH or XLOOKUP: which to use when the file has to open everywhere
VLOOKUP, INDEX/MATCH and XLOOKUP compared: syntax, exact match, looking left, surviving inserted columns, two-key lookups, and which apps have which.
How to build a monthly budget in Excel that adds itself up
Build a monthly budget in Excel or Google Sheets from scratch: planned vs actual by category, SUMIFS from a log, savings rate, and a twelve-month view.
Why your email breaks in Outlook, and what to do about it
Desktop Outlook renders email with the Word engine. What that removes, what survives, and how to write HTML email that holds together there and in Gmail.
Tailwind landing page checklist: what to check before you ship
Twenty-two checks for a Tailwind CSS landing page before it goes live: built CSS, dark mode, forms, images, accessibility, metadata — one line settles each.
MJML basics: from readable source to an email Outlook renders
What MJML is, how mj-section and mj-column compile to the tables Outlook needs, a shared theme file, and the commands that turn source into HTML you can send.