\ Perfect Temp Calculator /

Make midnight feeding
gentler、faster.

Don't keep your crying baby waiting.
Instantly calculate the 'Golden Ratio' of hot and cooled water.
A support app dedicated to formula preparation.

*No installation required · Completely Free

Peaceful night baby feeding scene

Do you have these worries?

Tired parent struggling with formula
  • 💭Panicking when baby cries...
  • 🫠Takes too long to cool down...
  • 😵‍💫Forget how many spoons I put in...
Calculation support on the go

Prevent "Too Hot"
milk while out.

Made milk at a park or mall but...
"It's too hot to drink!"
Have you ever had trouble finding a place to cool it down?

Estimate temperatures and volumes on the go.
Use clean equipment and water specified by the product.
Follow preparation instructions and check the actual temperature.

Happy parent feeding baby outdoors
Solution

What Milk Ratio Can Do

Leave the hard math to the app. You just pour the love.

Mixing hot and cold water illustration

Estimate Temperature and Volume

Estimate the ratio from water temperatures and volume.
Follow product instructions and check the actual temperature.

Water bath cooling calculation illustration

Calculate Cooling Water

Estimate water for cooling the outside of a bottle.
Cooling time and actual temperature are not guaranteed.

Voice recording and graphing illustration

Voice Record & Viz

Display spoken numbers such as “20, 40…”.
This does not save or share feeding records.

How to use

Using it is
very simple

Use calculations as estimates.
Always follow the product preparation instructions.

1

Read the product label

Check powder and water quantities and preparation steps.

↓
2

Enter conditions

Choose temperatures and final volume.

↓
3

Review estimates

Product quantities take priority. Do not set concentration by estimates alone.

↓
4

Prepare as instructed

Dissolve powder with water at least 70°C. Do not cool to drinking temperature first.

↓
5

Cool and check

Check the actual temperature before feeding.

Day & Night

Day or Night,
Gentle on eyes.

Does your bright phone screen wake you up during late night feeds?

Milk Ratio has a Dark Mode.
Don't wake the baby, protect parents' sleep.

2:00 AM

Late Night

Dark Mode

Protect Sleep

App light mode screenshot
App dark mode screenshot
Official preparation references

Why is "70°C" necessary?

We link to official preparation guidance. The app uses approximate heat-balance calculations and is not certified or reviewed by WHO or MHLW.

Sterilization over 70°C

Formula powder is not sterile. WHO/MHLW recommend 70°C+ water to kill bacteria like Sakazaki.

Guidelines:

  • • WHO/FAO: Safe preparation... Guidelines
  • • 厚生労働省: 調乳ガイドライン

Follow product-specific instructions

Follow product instructions for powder and water quantities, their order and water handling. Do not determine concentration from calculations alone or dilute prepared formula with extra water.

⚠️Always check temp on wrist. Cool with running water if too hot.

Sources:

  • • 森永乳業: 妊娠・育児情報サイト「はぐくみ」
  • • 株式会社明治: ほほえみクラブ「ミルクの作り方」

References

FAQ

FAQ

Q.What is Milk Ratio?

A free calculator for hot-to-cool water ratios, cooling water amounts and mixed temperatures. No registration or installation. Includes formulas, limitations and official preparation references.

Q.Can I use bottled water as cooled water?

Follow both formula and water labels for water selection, boiling and handling after opening. Soft water or baby-water labels alone do not establish that water can be used directly.

Q.Is installation required?

No, absolutely no installation needed. Just access https://milk.kurashitools.com on your browser. On iPhone, you can 'Add to Home Screen' to use it like an app.

Q.What is the ideal milk temperature?

The initial target is 38°C and can be changed. This is a calculation setting, not a guarantee of suitability for every baby. Check the actual temperature before feeding.

Q.Why use 70°C hot water?

Powdered formula is not sterile. WHO and MHLW advise preparation with water no cooler than 70°C. Do not cool to drinking temperature before dissolving powder; follow product quantities and instructions.

Q.What is cooled water (Yuzamashi)?

Water that has been boiled and then cooled. Handle it hygienically and follow product instructions for suitable water and storage.

Q.Can I use it on the go?

Yes, wherever you can use a browser. Product preparation instructions, hygienic equipment and water, and temperature checks still apply.

Q.Is it completely free?

Yes, completely free. No registration, minimal ads. We run this to help busy parents.

Q.How do I use voice recognition?

Allow microphone access in a supported browser to display spoken numbers. Check for recognition errors. This does not save or share feeding records.

Make milk making
more stress-free.

No installation needed.
Open browser and use immediately.

📱

Add to Home Screen

Use 'Share' -> 'Add to Home Screen'
to use like a native app.