Health · Fitness · Nutrition

Health Calculators

Eight tools for your body and goals — daily calories, body fat, BMR, TDEE, ideal weight, macros, protein and lean mass — alongside a clear look at global health, emerging viruses, the world's biggest pharma companies, and health insurance across Africa.

Daily Calorie Calculator

Your daily calorie needs, using the Mifflin-St Jeor equation.

Maintenance
Lose ~1 lb/wk
Gain ~1 lb/wk
Mifflin-St Jeor is the most accurate common formula. A 500 cal/day deficit ≈ 1 lb/week loss. Don't go below ~1,200 (women) or ~1,500 (men) without medical advice.

Body Fat Calculator

Estimate body fat percentage using the U.S. Navy method (measurements in cm).

Body fat
Category

BMR Calculator

Basal metabolic rate — calories your body burns at complete rest.

Basal metabolic rate

TDEE Calculator

Total daily energy expenditure across all activity levels.

Sedentary
Light
Moderate
Active
Very active

Ideal Weight Calculator

Healthy weight estimates from your height and sex.

Devine formula
Robinson formula
Healthy BMI range
Formulas give a single figure; the healthy BMI range (18.5–25) is a more realistic target band. Body composition matters more than any single number.

Macro Calculator

Split your daily calories into protein, carbs and fat.

Protein
Carbs
Fat

Protein Intake Calculator

Your daily protein target based on weight and goal.

Daily protein
Per meal (×4)

Lean Body Mass Calculator

Estimate lean mass and fat mass using the Boer formula.

Lean body mass
Fat mass
Body fat
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Note: These calculators and articles are for general education — they are not medical advice. For personal health decisions, screening, symptoms or treatment, always consult a qualified healthcare professional.

Global health: a region-by-region picture

Health is deeply unequal across the world. A baby born in a wealthy country can expect to live into their 80s; in parts of sub-Saharan Africa, life expectancy is still in the low 60s. The burden of disease differs by region too: high-income countries mostly battle chronic "lifestyle" conditions — heart disease, cancer, diabetes and dementia — while lower-income regions carry a double burden of those plus infectious diseases like malaria, HIV and tuberculosis, which together still kill roughly 2 million people a year. Access to doctors, medicines and clean water varies enormously, and most of the world's health spending is concentrated in North America and Europe, even though the greatest need is elsewhere.

Emerging viruses and the "next pandemic"

COVID-19 was a wake-up call, and scientists now watch the horizon constantly. The virus of greatest current concern is H5N1 bird flu, which has spread through wild and domestic birds and, more worryingly, jumped into mammals — including dairy cattle and a number of farm workers in the United States. So far it doesn't spread easily between people, but influenza viruses mutate fast, and a version that did could be dangerous. Related strains such as H5N6 are also being tracked closely.

The WHO uses the phrase "Disease X" for an unknown pathogen that could cause the next pandemic — COVID-19 was, in effect, the first Disease X to arrive. Other watch-list threats include mpox, Marburg, Nipah, and mosquito-borne viruses like dengue, Zika and chikungunya, whose range is expanding as the climate warms. Running underneath all of this is antimicrobial resistance — germs evolving to defeat our antibiotics — which the WHO calls one of the biggest long-term threats to global health.

Disease as a weapon — and the global ban on it

Deliberately using disease to cause harm is one of the oldest fears in warfare, and the world has responded by outlawing it. The Biological Weapons Convention (BWC), in force since 1975 and signed by more than 180 countries, bans the development, production and stockpiling of biological weapons entirely — it was the first treaty to prohibit a whole category of weapons. Using disease as a weapon is a war crime under international law. Several historical state programmes existed during the 20th century but were dismantled under this framework. Today the genuine concern among experts is not open state use but biosecurity: preventing accidents, securing laboratories, and responsibly governing "dual-use" research that could be misused. Strengthening this oversight — and global disease surveillance — is how the world guards against both natural pandemics and deliberate misuse. (This is a policy overview only; it contains no technical information.)

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The world spends heavily on health — who are the big players?

Healthcare is one of the largest sectors on Earth, and the pharmaceutical industry alone is worth around $1.6 trillion a year. The top 20 drugmakers together bring in roughly $900 billion annually. Here are the major players by recent annual revenue:

#CompanyCountryApprox. revenue
1Johnson & JohnsonUSA~$90B+ (total)
2Eli LillyUSA~$65B
3Merck & Co.USA~$64B
4PfizerUSA~$63B
5AbbVieUSA~$56–61B
6AstraZenecaUK~$54–59B
7RocheSwitzerland~$57–70B
8NovartisSwitzerland~$50–54B
9SanofiFrance~$47B
10Bristol Myers SquibbUSA~$48B
11Novo NordiskDenmark~$40B+
12GSKUK~$40B
13AmgenUSA~$37B
14Gilead SciencesUSA~$29B
15TakedaJapan~$30B
16Bayer (pharma)Germany~$20B+
17Boehringer IngelheimGermany~$26B
18ModernaUSA~$3–7B
19SinopharmChina~$80B (distributor)
20Viatris / othersUSA~$14B

Figures are approximate recent annual revenues and mix fiscal years and reporting bases (some are total-company, some pharma-only); rankings shift year to year. Sinopharm is primarily a distributor. Verify current numbers in each company's annual report.

How the last decade — and post-COVID — reshaped pharma

The past decade transformed the industry. COVID-19 briefly made Pfizer the biggest drugmaker on Earth, with revenue topping $100 billion in 2022 thanks to its vaccine and antiviral. As the pandemic faded, that COVID income collapsed and Pfizer's revenue fell by roughly a third. The new growth engine is weight-loss and diabetes drugs: the GLP-1 medicines from Eli Lilly (Mounjaro, Zepbound) and Novo Nordisk (Ozempic, Wegovy) have driven explosive growth — Eli Lilly's revenue jumped about 45% in a single year and it became one of the world's most valuable companies. Post-COVID, big pharma continues to profit heavily from health crises and chronic-disease demand, which fuels an ongoing global debate about drug pricing, access and fairness — especially for poorer countries.

Major health breakthroughs of the last decade

How to keep healthy

Most of what protects your health is simple, free and within your control:

Health insurance across Africa

Access to affordable care increasingly means having health insurance. Many African nations now run national schemes, alongside private and regional insurers. Details, prices and eligibility change often — always confirm on the official site.

CountryMain schemeWhere to find it
GhanaNational Health Insurance Scheme (NHIS) — established 2003, wide coveragenhis.gov.gh
NigeriaNational Health Insurance Authority (NHIA) — now mandatory nationwidenhia.gov.ng
KenyaSocial Health Authority (SHA), which replaced the NHIF in 2024sha.go.ke
RwandaMutuelles de Santé — community-based, covers most of the populationrssb.rw
South AfricaPrivate medical schemes (e.g. Discovery Health) while national NHI rolls outdiscovery.co.za
UgandaNational scheme in progress; private cover via AAR, Jubilee, Prudential, UAPhealth.go.ug
Regional privateJubilee Health, AAR, Britam, Old Mutual, Sanlam — operate in several countriesInsurer websites

Scheme names, websites and rules change; this is a starting point, not an endorsement. Verify current products, prices and eligibility directly with each scheme or a licensed insurer in your country.

Frequently asked questions

How many calories should I eat a day?

It depends on age, sex, size and activity. The calculator uses Mifflin-St Jeor to find maintenance calories; eat ~500 below to lose about a pound a week, above to gain. Don't drop below ~1,200 (women) or ~1,500 (men) without medical guidance.

What's the difference between BMR and TDEE?

BMR is what you burn at complete rest; TDEE is BMR multiplied by an activity factor, so it reflects your real daily burn including movement and exercise.

How much protein do I need?

About 0.8 g/kg if sedentary, and 1.4–2.0 g/kg if active or building muscle. For 70 kg that's roughly 56 g up to ~140 g. The Protein tab estimates your target.

Which are the world's biggest pharma companies?

By recent revenue: Johnson & Johnson, Eli Lilly, Merck, Pfizer, AbbVie, AstraZeneca, Roche, Novartis, Sanofi, Novo Nordisk and Bristol Myers Squibb. GLP-1 drugs lifted Lilly and Novo Nordisk; Pfizer fell after its COVID peak.

What health insurance is available in Africa?

National schemes include Ghana's NHIS, Nigeria's NHIA, Kenya's SHA (which replaced the NHIF) and Rwanda's Mutuelles de Santé. South Africa leans on private schemes like Discovery. Regional insurers (Jubilee, AAR, Britam, Old Mutual) operate across borders.

What are the biggest emerging disease threats?

H5N1 bird flu (now in mammals) is watched most closely for pandemic potential; "Disease X" is the WHO's term for an unknown future pandemic pathogen. Malaria, HIV and TB still kill ~2 million a year, and antimicrobial resistance is a rising threat.

Educational information only, not medical, financial or professional advice. Calculator results are estimates. Company figures, insurance details and health data are approximate and change over time — verify with official sources. Consult a qualified professional for personal health decisions.

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