Warsaw Method Calculator
Use our Warsaw Method calculator to estimate insulin dosing for meals using fat and protein (FPU) alongside your insulin-to-carb (IC) ratio. Includes what the Warsaw method is in diabetes management, how an FPU calculator works, and the core Warsaw method formula steps.
What Is the Warsaw Method?
The Warsaw method is a diabetes meal-bolus approach that estimates insulin needs for fat and protein, not just carbohydrates. It’s commonly discussed in the context of Type 1 diabetes and pump therapy where fat/protein can cause delayed, extended blood sugar rises.
A key idea is converting calories from fat and protein into a “carb equivalent” amount using FPU (Fat-Protein Units). This is why you’ll sometimes see it referred to as an FPU calculator.
This calculator helps estimate FPU, carb equivalent, suggested insulin units (based on your IC ratio), and an extended bolus duration estimate. Always follow your clinician’s plan and your pump guidelines.
Warsaw Method Formula
There are a few variations in how people apply the Warsaw method. This calculator uses a common structure: convert fat/protein calories into FPUs, convert FPUs into carb equivalents, then apply your insulin-to-carb (IC) ratio.
Fat has ~9 kcal/g; protein has ~4 kcal/g.
1 FPU is commonly defined as 100 kcal from fat+protein.
A common Warsaw-method mapping is 1 FPU ≈ 10 g carbs (used to estimate insulin impact).
If your IC ratio is 10, that means 1 unit covers 10 g carbs.
Higher FPU meals often need a longer extended bolus to match delayed glucose rise.
How to Use the Warsaw Method Calculator
- 1
Enter fat and protein amounts for the meal (use grams if available from nutrition labels).
- 2
Enter your insulin-to-carb (IC) ratio (grams of carbs covered by 1 unit of insulin).
- 3
The calculator estimates total calories from fat + protein, then converts that into FPU (per 100 kcal).
- 4
It converts FPU into a carb-equivalent amount, then estimates insulin units using your IC ratio.
Frequently Asked Questions
It’s an approach that estimates insulin needs for fat and protein by converting fat+protein calories into FPUs (Fat-Protein Units) and then into a carb-equivalent amount for dosing.
An FPU calculator estimates Fat-Protein Units—often defined as 100 kcal from fat and protein—then converts that into carb equivalents to help estimate insulin needs.
No. It’s an estimate. Individual responses vary based on digestion, activity, insulin sensitivity, meal composition, and timing. Many people fine-tune it using CGM trends.
High-fat and high-protein meals can cause delayed glucose rises even with low carbs. The Warsaw method attempts to account for that delayed effect.
Typically people using insulin therapy who notice delayed post-meal rises from fat/protein. It’s best used with clinician guidance, especially if you use extended/dual boluses.