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Water and food

Water and food for a group

Total water, energy and kilograms of a staple food to feed a group for several days.

L

Sphere: 15 L with cooking and hygiene; 2.5-3 L for drinking only.

kcal

2100 kcal is the planning average for a mixed population (WHO, WFP, Sphere). Heavy physical work: 2500-3500 kcal.

Energy per kg of dry or raw food, as stored.

%

In a typical aid ration cereal provides 60-70 %, pulses 10-15 % and oil 10-20 %.

Result

Total water
— L
Total energy
— kcal
Staple food needed
— kg
Staple food per person per day
— g

How it is calculated

Water (L) = people × days × L per person per day. Energy (kcal) = people × days × kcal per person per day. Food (kg) = energy × share (%) ÷ 100 ÷ kcal per kg.

Example. 10 people, 30 days, 15 L and 2100 kcal; wheat provides 70 %: water 10 × 30 × 15 = 4500 L; energy 10 × 30 × 2100 = 630 000 kcal; wheat 630 000 × 0.70 ÷ 3300 = 133.6 kg, that is 133 600 g ÷ 300 = 445 g per person per day.

Repeat the calculation for each food in the ration (for example, 70 % cereal, 15 % pulses, 15 % oil) and check that the shares add up to 100 %.

Keep in mind

  • Energy of raw or dry food from composition tables (USDA; FAO): wheat 3270-3400 kcal/kg depending on variety; white rice 3600-3650; maize 3650; dry pulses 3300-3800 (bean 3330, lentil 3520, chickpea 3780); potato 770; oil 8840; sugar 3870.
  • This tool only counts energy. A single-cereal diet falls short of quality protein, vitamins and minerals: combine cereal and pulses and add vegetables, fruit or fresh foods as soon as possible.
  • Add a 10-20 % margin for storage losses (moisture, insects, rodents) and wasted rations.
  • Children, pregnant and breastfeeding women, the sick and people doing hard work have different needs: 2100 kcal is a population average, not an individual figure. For malnutrition, consult health workers.

See also

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