How to Use Alligation Alternate Grid
Blend two concentrations step-by-step:
Enter High Strength
Input percentage of stock solution A (e.g. 70%).
Enter Low Strength
Input percentage of diluent or stock solution B (e.g. 20% or 0% for pure water).
Cross Subtract
Subtract target strength diagonally to find relative parts of each solution.
Scale to Total Volume
Multiply parts ratio by target total volume for exact liquid volumes (mL).
Key Features & Compounding Pharmacy
Compounding Grid Visualization
Displays full 3x3 alligation grid breakdown in real-time.
Diluent (0%) Water Support
Supports mixing stock concentrate with pure solvent/water (0%).
Exact Volume Dosing
Calculates precise volumes in mL, liters, or grams for ointments and fluids.
Pharmacy Compounding Guide: Alligation Alternate
Alligation Alternate is a classic practical method used in pharmaceutical calculations when blending two solutions of strength H (high) and L (low) to achieve target strength T:Parts of High = T - L and Parts of Low = H - T
Frequently Asked Questions
?Can target strength be higher than high strength solution?
No. By physical laws of mixing, the target strength T must strictly lie between the lower strength L and the higher strength H (L < T < H).