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Caffeine Intake Calculator

Calculate caffeine intake from beverage types and amounts. Personalized recommendations based on age, gender, and weight for optimal health management.

Current standard:400mg/day

General standard for adult males (age 18, weight 60kg)

mL

Calculation Result

Please add beverages

Age & Gender-Based Caffeine Guidelines

Adult Males

400mg/day

18-64 years

Adult Females

350mg/day

18-64 years

Elderly

♂350 / ♀300mg/day

65+ years

Pregnant/Nursing

200mg/day

Special caution required

Adolescents

100mg/day

12-17 years

Children

2.5mg/kg

Under 12 years

Important Notice

Individual differences exist. Adjust according to your health condition, medication status, and caffeine sensitivity. Consult your doctor if you have concerns.

Caffeine Content in Common Beverages (per 100mL)

Very High Caffeine

  • Espresso (200mg/100mL): 200mg
  • Pre-workout (150mg/100mL): 150mg

High Caffeine

  • Cold Brew (80mg/100mL): 80mg
  • Matcha (64mg/100mL): 64mg
  • Coffee (60mg/100mL): 60mg
  • Instant Coffee (57mg/100mL): 57mg

Medium Caffeine

  • Guarana (40mg/100mL): 40mg
  • Energy Drink (32mg/100mL): 32mg
  • Black Tea (30mg/100mL)・Mate Tea (30mg/100mL): 30mg
  • Frappuccino (25mg/100mL): 25mg

Low Caffeine

  • Green Tea (20mg/100mL)・Oolong Tea (20mg/100mL): 20mg
  • White Tea (15mg/100mL): 15mg
  • Cola (10mg/100mL): 10mg
  • Decaf Coffee (3mg/100mL): 3mg

How to Use

  1. STEP 1
    Click 'Get Personalized Recommendations' and enter your age, gender, and weight for more accurate recommendations (optional).
  2. STEP 2
    Select beverage type and enter the amount consumed (mL).
  3. STEP 3
    For multiple beverages, use '＋Add Beverage' to add more.
  4. STEP 4
    Press 'Calculate Caffeine Intake' to check total intake and health impact.
  • Caffeine content is a general guideline and varies greatly by product and brewing method.
  • Individual differences (weight, age, tolerance) greatly affect caffeine impact.
  • Pregnant/nursing women and those with heart conditions should follow medical advice.
  • Caffeine intake within 6 hours of bedtime may affect sleep quality.
  • This tool is for health management reference and does not replace medical diagnosis.

Tips

1

German chemist Friedlieb Runge first isolated caffeine from coffee beans in 1819, reportedly inspired by advice from Goethe.

2

Caffeine evolved as a natural pesticide to protect plants from insects. It paralyzes insects' nervous systems while being safe for mammals in moderate amounts.

3

Research shows that trace amounts of caffeine in flower nectar improve bees' memory, helping them remember and return to those flowers.

4

L-theanine in green tea moderates caffeine's stimulating effects while providing relaxation. This combination allows for improved focus while maintaining a calm state.

5

Nordic countries consume the most caffeine (400-500mg/day), while Japan is relatively moderate (200-300mg/day). Cultural beverage preferences greatly influence consumption patterns.

FAQ

  • QUESTION 1

    How long do caffeine effects last?

    Effects appear 30 minutes to 1 hour after consumption, with a half-life of about 3-5 hours. Complete elimination takes 6-8 hours.

  • QUESTION 2

    What happens with too much caffeine?

    Symptoms may include insomnia, anxiety, headaches, palpitations, gastrointestinal issues. Severe cases can lead to caffeine toxicity.

  • QUESTION 3

    Is decaf really caffeine-free?

    Not completely zero. While 97%+ is removed from regular coffee, small amounts (about 3mg/100mL) remain.

  • QUESTION 4

    Caffeine limits for children and pregnant women?

    Pregnant women: up to 200mg/day, children: up to 2.5mg per kg body weight, adolescents: up to 100mg/day are recommended.

  • QUESTION 5

    Coffee vs tea - which has more caffeine?

    Coffee generally contains more caffeine. Drip coffee (60mg/100mL) vs black tea (30mg/100mL). However, brewing time and leaf type can cause variations.

  • QUESTION 6

    What are the dangers of energy drinks?

    High caffeine concentration (50-80mg/100mL) plus other stimulants like taurine and guarana create synergistic effects, increasing risks of elevated heart rate and arrhythmias.

  • QUESTION 7

    How does caffeine affect sleep?

    Caffeine consumption even 6 hours before bedtime can reduce sleep quality. It decreases deep sleep (NREM) and increases nighttime awakenings. Individual sensitivity varies significantly.

  • QUESTION 8

    Is caffeine effective before exercise?

    3-6mg/kg body weight taken 30-60 minutes before exercise improves endurance, promotes fat burning, and reduces fatigue. However, watch for dehydration due to diuretic effects.

This information is general guidance. Consult doctors, nutritionists, or medical institutions for detailed advice.

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