Yeast Conversion Calculator
Convert by weight among instant, active dry and fresh yeast using common approximate ratios: 1 part instant is about 1.25 parts active dry or 3 parts fresh.
Last updated · View algorithm, constants and default inputs (JSON)
Converted amount (g)
About this calculator
Convert a positive weight among instant, active dry and fresh commercial yeast using the approximate ratios shown. Ratios vary by brand and recipe; follow product or recipe guidance when available. The teaspoon figure is a rough instant-yeast volume estimate. Optionally enter flour weight to express instant-equivalent yeast as a percentage of flour. Leave it at zero when you only need yeast conversion.
Worked example
calculated with the default values below
Yeast amount by weight 7 g · From Instant yeast · To Active dry yeast · Flour weight in the recipe 0 Converted amount 8.750 g · As instant yeast 7.000 g · As active dry yeast 8.750 g · As fresh yeast 21.000 g · Approximate teaspoons 2.26 tsp
General background references
Disclaimer
These calculators give general cooking guidance. Ingredient density, oven calibration, altitude and equipment all vary, and safe minimum internal temperatures always take precedence over timings. Follow the food-safety advice issued by your national authority.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
R = A × t[from] × f[to]
- A
- Amount (g)
- t
- Source factor (1, 0.8 or 1/3)
- f
- Target factor (1, 1.25 or 3)
- R
- Converted amount (g)
t: instant 1, active dry 0.8, fresh 1/3; f: instant 1, active dry 1.25, fresh 3. Teaspoons of instant ≈ (A × t) ÷ 3.1; result shown to 3 decimals.
Frequently asked questions
Why are the yeast ratios approximate?
The calculator uses instant = 1, active dry = 1.25 and fresh = 3 as its comparison factors. Baking guidance varies by recipe and brand; for example, King Arthur recommends multiplying fresh yeast by about 0.33 to substitute instant or active dry. Use the recipe or manufacturer ratio when provided. Teaspoons are an additional rough mass-to-volume estimate. [King Arthur Baking](https://www.kingarthurbaking.com/blog/2023/04/24/how-to-bake-with-fresh-yeast).