What it helps you decide
Plot measured pH and aw against key FDA classification boundaries.
Shelf-stability screening
Put measured pH and water activity in the same risk screen.
Plot laboratory or calibrated readings against the FDA 4.6 pH and 0.85 water-activity boundaries and see the next validation step immediately.
Start with the example
The values already filled in are a working example—not a recommendation.
- 1Choose the closest starting point.
- 2Replace the example with your real details.
- 3Read the live result and its important limits.
Your numbers
Measured product controls
Use the filled example first. Then replace each field with a measured value or your best current estimate.
Step 1Answer one question at a time. Your example values stay available.
Important limit
No pH + aw calculator can declare a food safe.
Product composition, pathogens, molds and yeasts, packaging, thermal process, preservatives, storage, measurement uncertainty, and jurisdiction all matter. Use representative finished-product testing and a qualified process authority or food-safety professional before making shelf-stability decisions.
About this free compliance, labels & traceability tool
How to use the pH + Water Activity Safety Matrix
Plot measured pH and aw against key FDA classification boundaries. The calculator runs privately in your browser and is designed to make the assumptions behind the answer visible.
What to have ready
Bring the exact formula or product facts, supplier documents, intended market, package details, and the current official source that governs the decision.
Key inputs: Finished equilibrium pH; Measured water activity (aw); Intended storage; Package; Reading source.
How to use the result
Use the output as a documented draft or research aid. Verify it against current requirements and obtain qualified review before printing, selling, or making a safety claim.
Complete workflow guide
HACCP and food safety systems
A useful plan tells people what to check, when to check it, what counts as acceptable, and what to do when a result is missing or outside the limit.
Learn the workflow
Helpful guides for this calculator
Food Safety & Shelf LifeHow to Create a Bakery HACCP Plan: Process Flow, Hazards and CCP Examples
Understand the structure of a bakery HACCP or preventive-controls plan without copying generic hazards, critical limits, or CCPs that may not fit your facility and products.
Read the guide →Food Safety & Shelf LifepH and Water Activity: What Food Makers Need to KnowUnderstand why pH and water activity measure different barriers and why a calculator cannot replace a scheduled process or laboratory shelf-life validation.
Read the guide →Ready for the connected version?
Turn the calculation into a repeatable workflow.
Batch Scale connects recipes, materials, costs, inventory, production, sales, and your storefront in one workspace.