Sourdough Starter Calculator
Map out a full week of bakes, see how much starter you will need, and dial in the right amount to discard. This is the same planning tool our team uses in the bakery every week.
Plan your schedule
Set how many loaves you are baking each day, adjust the starter you keep on hand, then hit Recalculate. The table shows how much starter to reserve for tomorrow, when to discard, and how your starter will grow after feeding.
| Day | Loaves Needed | Starter Available | Take for Tomorrow's Loaves | Discard Amount | After Discard | After Growth (x3) | Notes |
|---|
Summary
Total Loaves
0
Total Starter Required
0g
Total Discard
0g
How to use this calculator:
- Enter the number of loaves needed each day.
- Adjust the "Minimum Starter" amount (default 80g) to match your preference.
- Adjust the "Starter per Loaf" amount (default 120g) to match your recipe.
- Sunday's "Starter Available" is always editable - enter what you actually have.
- Days 1-6 auto-calculate from previous day's growth - check "Override" to use manual amounts.
- Override mode shows blue highlighting and preserves your entered amounts.
- The calculator shows how much starter to take for loaves and how much to discard.
- After discard, the remaining starter is tripled (fed and grown).
- Red rows indicate insufficient starter - increase the starting amount.
- Orange discard amounts suggest you might be maintaining too much starter.
Tips from the 48V crew
- Dial in your starting amount so rows stay green - red means you will come up short.
- High discard numbers are a clue to scale back what you are keeping between feeds.
- Remember to feed right after taking what you need for tomorrow's loaves so the growth math holds true.