Yeast Conversion Calculator
Yeast Type Conversion Reference
Equivalent amounts of each yeast type.
| Active Dry | Instant | Fresh/Cake | Starter (100% hyd.) |
|---|---|---|---|
| 1 tsp (3.1g) | ¾ tsp (2.3g) | 1 tbsp (9.3g) | 75g (⅓ cup) |
| 2¼ tsp (7g) | 1¾ tsp (5.3g) | 0.6 oz (17g) | 170g (¾ cup) |
| 1 tbsp (9.3g) | 2¼ tsp (7g) | 1 oz (28g) | 225g (1 cup) |
| 4½ tsp (14g) | 1 tbsp (10.5g) | 1.2 oz (34g) | 340g (1½ cups) |
How We Calculate This
This yeast conversion calculator uses established formulas and industry-standard data to provide accurate estimates.
- Enter your specific values into the calculator fields above
- Our algorithm applies the relevant formulas using your inputs
- Results are calculated instantly in your browser — nothing is sent to a server
- Review the detailed breakdown to understand how each factor affects your result
These calculations are estimates based on standard formulas. For critical decisions, always consult a qualified professional.
How to Convert Oven Recipes to Air Fryer
Different yeast types have different concentrations of active yeast cells. Converting between them requires knowing the relative potency of each type.
The basic rule:
- Instant yeast = Active Dry × 0.75 (instant is more concentrated)
- Fresh/cake yeast = Active Dry × 3 (fresh has more moisture, less concentrated)
- Sourdough starter (100% hydration) ≈ Active Dry × 42 by weight — and you must reduce flour and water in the recipe to compensate
Active dry yeast should be dissolved in warm water (105-110°F) before use. Instant yeast can be mixed directly into flour. Fresh yeast should be crumbled into liquid. Sourdough starter should be active and bubbly (fed 4-12 hours prior).
When Would You Use This Calculator?
This yeast conversion calculator is designed for anyone who needs quick, reliable estimates without complex spreadsheets or professional consultations.
- When you need a quick estimate before committing to a purchase or project
- When comparing different options or scenarios side by side
- When planning a budget and need to understand potential costs
- When you want to verify a quote or estimate you've received from a professional
- When teaching or learning about the concepts behind these calculations
Frequently Asked Questions
Can I substitute instant yeast for active dry yeast?
Yes. Use 25% less instant yeast than the active dry amount called for. So if a recipe calls for 1 teaspoon active dry, use ¾ teaspoon instant. Instant yeast can be added directly to dry ingredients without proofing in water first.
How do I substitute sourdough starter for commercial yeast?
Replace each teaspoon of active dry yeast with about ⅓ cup (75-80g) of active sourdough starter. Since starter is half flour and half water (at 100% hydration), reduce the recipe flour by about 38g and liquid by about 38g to keep the ratios correct.
What is fresh (cake) yeast and where do I find it?
Fresh yeast is a moist, crumbly block of live yeast sold refrigerated. It is highly perishable (lasts 1-2 weeks). Find it at bakery supply stores, some supermarket deli sections, or European grocery stores. It gives a slightly different flavor that some bakers prefer.
Does the conversion affect rise time?
Slightly. Instant yeast works about 15-20% faster than active dry. Fresh yeast rises similarly to active dry. Sourdough starter is much slower — expect 2-3x the rise time. Temperature, hydration, and flour type also affect rising time.
How much yeast is in one packet?
A standard yeast packet contains 2¼ teaspoons or 7 grams of active dry or instant yeast. This is enough to leaven up to 4 cups of flour. One 0.6 oz cake of fresh yeast is equivalent to one packet of dry yeast.
Can I use expired yeast?
Yeast loses potency over time. Test by dissolving it in warm water with a pinch of sugar. If it foams within 10 minutes, it is still active. If expired yeast is weak, you can use 25-50% more to compensate, but results may be inconsistent.