Formulator's Toolkit

"Type a percentage. Everything else calculates."

You do not need a chemistry degree to formulate skincare. You need a scale, a few rules, and somewhere to do the math — and this is the math, done for you.

The Formulator's Toolkit is two spreadsheets that handle the arithmetic and the record-keeping of home formulating: a Formulation Calculator with Serum, Whip, Balm, and Cream tabs, and a Batch & Ingredient Tracker for every batch you make and every ingredient you buy. Enter a percentage and the grams, ounces, phase totals, and cost per jar fill themselves in. It is the bench companion to the Duplika guides, and it works with any formula, from any source.

The Formulation Calculator

• Four product tabs — Serum, Whip, Balm, Cream. Each opens with a complete sample formulation so you can see exactly how it works. Overwrite it with your own.
• Enter a percentage; grams and ounces fill themselves. Set the batch size once, in grams or ounces, and every weight updates. Scale from 50 g to 500 g without touching the formula.
• Water balances automatically so your total is always exactly 100.00%. The Total row turns green when you are there and tells you precisely how far over or under you are when you are not — so a formula literally cannot come out wrong.
• Phase subtotals — your water phase, oil phase, cool-down actives, and preservative at a glance. The oil-phase number is the one that decides whether a cream feels like a gel or a night cream.
• Know what a jar costs before you buy the jars. Add what you pay per gram and get the cost of the batch, the cost per gram, the cost per finished unit, and a suggested retail price on the same sheet.
• Suggested usage ranges for 30 ingredient types — humectants, emulsifiers, fatty alcohols, butters, retinoids, preservatives — by phase and product, so you always know whether 4% is generous or reckless.

The Batch & Ingredient Tracker

• Batch Log — lot number, product, date made, batch size, final pH, preservative, packaging, notes. Type the shelf life in months and the sheet calculates the expiration date, counts the days remaining, and colour-codes every batch Fresh, Use soon, or Expired. No more mystery jars.
• Ingredient library — INCI name, supplier, product link, and price ÷ package size = cost per gram, calculated. Plus supplier lot numbers, ingredient expiry with a 60-day warning, and a reorder flag when you are running low.
• Suppliers — pre-filled with five vetted cosmetic suppliers, with room for your own accounts, shipping notes, and discount codes.
• Packaging & Equipment — jars, bottles, pumps, labels, scale, pH strips, with cost per unit.
• Lot Number Guide — a simple, consistent system so every jar traces back to a row in your log. Increasingly the expectation for anyone who sells.

Who it's for

Anyone who has made one batch and thought I should be writing this down. Beginners get a calculator that will not let a formula come out wrong. Experienced formulators get the costing and traceability system they would otherwise have to build themselves on a Sunday.

How it works

Download two files. Open them in Excel or Numbers, or upload to Google Sheets (File → Import) and use them free in your browser, on your laptop or your phone. Shaded cells are yours to type in; everything else is a formula. A Start Here tab in each file walks you through it, and a short illustrated user guide is included.

The details

• Instant digital download: 2 spreadsheet files (.xlsx) + a user guide (PDF).
• Works in Microsoft Excel, Apple Numbers, and Google Sheets. No macros, no add-ons, nothing to install, no subscription.
• 200 rows per log, filters on every tab, print-ready layouts for the bench.
• Sample formulations are drawn from Plump It Up, Whip It Up, Cream of the Crop, and Balm It Up — For Less. The guides are sold separately; the toolkit works with any formula you like.

For personal and small-batch use. Suggested usage ranges are starting points, not rules — always follow your supplier's specification sheet. Not medical advice; patch test every finished product. Due to the instant, digital nature of this product, all sales are final.

Basically the same thing — with the math done.