体重、年齢（子犬／成犬／シニア）、活動量、フードのカロリー密度から、愛犬の1日の必要kcalとフード量（カップ／グラム）を計算。ブランド別プリセット付き。
| 食事回数 / 日 | kcal / 食 | カップ / 食 | グラム / 食 |
|---|
RER（安静時エネルギー要求量）= 70 ×（体重kg）^0.75。MER（1日の必要量）= RER × ライフステージ係数: 子犬2〜4か月 ×3、子犬4〜12か月 ×2、成犬（未去勢/未避妊）×1.8、成犬（去勢/避妊済み）×1.6、シニア犬 ×1.4。活発な犬は+20%、減量目標はRERの×1.0、増量目標は×1.6です。
ドライフード1標準カップ ≈ 100g（キブルの大きさにより90〜120gの幅があります）。正確を期すため必ずキッチンスケールで重さを量ってください。ボディコンディションスコア（肋骨が見えずに触れる状態が目安）に基づき、2週間ごとに±10%の範囲で量を調整してください。
Daily calories start from Resting Energy Requirement, RER = 70 × (body weight in kg) raised to the 0.75 power. That is multiplied by a life-stage factor — Puppy 2–4 months ×3.0, Puppy 4–12 months ×2.0, Adult ×1.6, Senior ×1.4 — and then by an activity factor: Sedentary 0.9, Normal 1.0, Active 1.2, Very active / working 1.4. An intact adult uses 1.8 rather than 1.6. Cups are simply the resulting calories divided by the kcal-per-cup figure, and grams follow from cups.
The kcal per cup value matters more than most owners expect. At 20 kg on the defaults, moving from the generic store brand at 350 to Purina Pro Plan at 410 changes the portion by about 15 percent for exactly the same calories, so set Food to Custom and enter the number printed on your own bag. Weight goal is the other big lever: Lose weight drops intake to RER alone, while Gain weight raises the multiplier.
Grams come from a fixed assumption that one cup of dry kibble weighs 100 g, and real kibble runs roughly 90 to 120 g per cup depending on piece size — weigh one level cup on a kitchen scale and trust grams from then on. The intact adjustment applies only to the Adult stage, and Lose weight discards age and activity entirely. None of this substitutes for a body condition score or veterinary advice.
Resting energy is 70 times 20 to the 0.75 power, about 662 kcal. A neutered adult at normal activity multiplies that by 1.6 for roughly 1059 kcal a day, which at 370 kcal per cup works out to about 2.86 cups of food.
Because the cup figure is calories divided by calorie density. The presets run from 350 kcal per cup for a generic store brand up to 410 for Purina Pro Plan, so the same dog needs noticeably fewer cups of the denser food.
Selecting Lose weight sets intake to resting energy exactly, discarding the age and activity multipliers altogether. That is an aggressive target, so use it under a vet-supervised plan with regular reweighing rather than running it indefinitely on your own judgement.
The table under the result shows two, three and four meals with kcal, cups and grams for each. Splitting does not change the daily total; it mainly affects hunger between meals, and matters most for puppies, who carry the highest multipliers here.
That is the fixed conversion this tool uses, and it is only an average. Real kibble runs roughly 90 to 120 g per cup depending on piece size and shape, so weigh one level cup of your own food once and use the gram figure instead.
