1. Find the original total
Add every component after normalising compatible units into grams or millilitres.
original total = sum of original quantitiesFormula Scaling Calculator
Scale a professional-entered formula to a target total or by a multiplier while preserving its exact component ratios.
Compare exact and practical rounded quantities, add optional package costs, and copy, print or download the result. Free, no registration required.
Inputs and results are excluded from custom analytics, URLs and calculator network requests. They remain in this mounted page unless you explicitly prepare a short-lived source payload. That payload is valid for 30 minutes and is removed at expiry while this calculator is mounted; after navigation, any expired bytes are rejected and removed when the calculator or a destination next reads them. It is also removed when the tab closes and is not an account save.
How proportional scaling works
The calculator uses strict decimal arithmetic. It does not round exact component quantities before completing the calculation.
2. Find one scale factor
In target mode, divide desired total by original total. In multiplier mode, use the entered multiplier.
factor = target total ÷ original total3. Scale every component
Multiply each original quantity by the same factor. This preserves the entered ratio within the decimal calculation precision.
exact quantity = original quantity × factorExact is mathematical. Practical is explicit.
Practical rounding uses nearest-increment, half-up rounding on each component in its entered unit. A value exactly halfway between two increments rounds upward for positive quantities.
The calculator then reports each quantity difference, each ratio deviation, the practical total and the difference from target. It never redistributes that difference and never “balances” a final component.
Fictional worked example
- Original
- 30 g + 60 g = 90 g
- Target
- 67.5 g
- Scale factor
- 0.75×
- Exact result
- 22.5 g + 45 g = 67.5 g
- Nearest 0.5 g
- 22.5 g + 45 g = 67.5 g
These are fictional quantities for demonstrating ratio maths, not a formulation recommendation.
Assumptions and limitations
Use the calculator as a quantity tool inside your own professional decision-making.
- At least two components are required, and the original total must be greater than zero.
- Zero-quantity components are preserved and remain zero after scaling.
- Mass and volume cannot coexist in one scaling group; no density is assumed.
- Optional costs are direct product costs for components with complete compatible package data. They are not profit, price, labour, overhead, tax or technical guidance.
- Product names, labels and notes are not validated as chemistry and never enter analytics.
- Original and adjusted formulas remain separate in the source payload. Product matching, client selection, saving and formula lineage require later destination review.
Formula scaling FAQ
Does this calculator recommend a colour formula?
No. It only scales quantities and ratios that a professional has already entered. It does not recommend products, shades, developer, processing or technical suitability.
What is the difference between exact and practical quantities?
Exact quantities preserve the entered ratios using strict decimal arithmetic. Practical quantities round each exact component independently to your selected increment. The calculator reports any total and ratio difference and does not rebalance a component.
Can I mix grams and millilitres in one formula?
No. A scaling group can contain compatible mass units or compatible volume units, but never both. The calculator does not infer density or convert mass to volume.
How are optional direct product costs calculated?
For each component with complete package data, package price is divided by its normalised package quantity, then multiplied by the original, exact or practical usage. Each displayed line rounds to currency cents before totals are added.
Does TintLedger save my formula automatically?
No. Calculator fields remain in the mounted page. The explicit Keep both formula versions action can prepare a short-lived browser-session source payload, but no destination adapter writes it to an account in this release.