Koi Feeding Calculator
Koi daily and monthly food from fish size and water temp.
What it does
Koi appetites follow the thermometer. Warm ponds digest full rations, cool ponds take light meals, and cold ponds fast entirely.
The tool above feeds a percent of body weight. Six 16 oz koi in warm water need 2.4 oz a day, or 4.5 lb a month. The metric match is 450 g toward 68 g a day.
Bands keep ponds clean. Warm 2.5 % suits summer growth, cool 1 % suits shoulder seasons, and cold fasting below 50 F protects fish that cannot digest.
Meals split the day. Two feedings eaten inside five minutes beat one dump that sinks to the filter.
Filters close the loop. Rinse media in pond water, never tap, so feeding never costs the bacteria that clear waste.
How to use
- Pick imperial (oz) or metric (g).
- Enter koi count and average weight.
- Pick water band: warm suits summer.
- Read daily first, then monthly.
- Read season note.
- Feed to five minute clears.
Formula
- koi
- Fish count.
- weight
- Average body weight.
- temp
- Cold, cool, or warm water.
Weight is oz imperial and grams metric. Cold band fasts fish below 50 F, so daily reads zero by design.
Worked example
Example: 6 koi, warm water
Imperial defaults: 6 koi at 16 oz in warm water. These are also the default values, so the page opens on this answer.
- Pond: 6 koi at 16 oz each.
- Water: warm, so 2.5 % of body weight.
- Daily: 6 x 16 x 0.025 = 2.4 oz.
- Month: 2.4 x 30 / 16 = 4.5 lb.
- Tool shows 2.4 oz per day, 4.5 lb per month, Full feeding in warm water.
Reference table
| Fish | Warm daily | Cool daily |
|---|---|---|
| 4 | 1.6 oz | 0.6 oz |
| 6 | 2.4 oz | 1 oz |
| 10 | 4 oz | 1.6 oz |
| 6 metric | 68 g | 27 g |
Limits
- Feeding guide only. Health needs pond vets.
- Cold fasting is by design, not error.
- Overfeeding fouls filters fast.
- New ponds cycle before full rations.
Common mistakes
- Winter feeding below 50 F.
- One big dump instead of two meals.
- No thermometer, guessing bands.
- Rinsing filters in tap water.
- Skipping spring ration steps.
Try it yourself
Quick checks. Answers sit tucked under each question.
4 koi at 16 oz, cool water?
Daily is 4 x 16 x 0.01 = 0.6 oz. Monthly is 0.6 x 30 / 16 = 1.1 lb after rounding (1.125).
10 koi at 450 g, warm metric?
Daily is 10 x 450 x 0.025 = 112.5, shown as 113 g after rounding (112.5). Monthly is 112.5 x 30 / 1000 = 3.4 kg after rounding (3.375).
Questions
Food per day?
Multiply fish by weight by percent. Here 6 x 16 x 0.025 = 2.4 oz a day.
Warm versus cold?
Warm 2.5 %, cool 1 %, cold fasting below 50 F. Digestion follows water temp.
Food per month?
Multiply daily by 30 and convert. Here 2.4 x 30 / 16 = 4.5 lb a month.
How much per meal?
Feed what vanishes in five minutes, twice daily in warm water. Leftovers foul filters.
Spring warmup counts?
Yes. Spring warmups swing temps, so step rations with the thermometer.
Does this treat illness?
No. Ulcers and bloat need pond vet care.