SunKiss calculator
Calculate how much sunscreen you need
The estimate uses 25 mL per application every three hours and compares 200 mL bottles with 30 g SunKiss applications. Your data stays in the browser and is never stored.
Approximate estimate, not medical advice. Always follow the product label and guidance from your doctor or paediatrician.
The basis of the calculation: 25 mL per application
To keep the result clear and comparable, the calculator uses a fixed amount of 25 mL for each complete application. Height and weight no longer change the result, so those two fields have been removed.
This amount represents one application, not a full day's requirement. The total depends on time outdoors, the number of days and any extra reapplications.
Apply it to all exposed areas
The planned amount should be distributed evenly over all skin not covered by clothing or swimwear. Do not overlook the face, neck, ears, arms, legs, tops of the feet, hairline and back.
The calculator provides a planning estimate. Product directions and advice from a doctor or paediatrician always take precedence.
How often to reapply
The calculator schedules a new application every three hours. For example, seven hours outdoors corresponds to three planned applications: the initial one and two renewals during the day.
You can add extra reapplications after swimming, heavy sweating or towel-drying. Product directions always take precedence in real use.
How long a 200 mL bottle really lasts
Dividing 200 mL by the fixed 25 mL amount gives eight complete applications. Under this model, one person spending seven hours at the beach uses three applications during the day, totalling 75 mL.
This is why a seemingly large bottle can run out much faster than expected. The calculator converts your personal estimate into 200 mL bottles and always rounds up to a whole bottle.
200 mL bottles or SunKiss applications: how to read the comparison
The calculator compares two different units. First, it converts the total requirement into whole 200 mL bottles. It then converts the same total into equivalent SunKiss applications, using the fixed estimated amount of 30 g of product per dispense.
Because each SunKiss application dispenses more than the 25 mL used as the calculation baseline, the number of equivalent applications may be lower. This comparison concerns total product quantity only: it does not suggest extending the reapplication interval. No prices are shown.
Children and infants: an important distinction
For children and teenagers, the amount must still cover all exposed skin; body size matters more than age. For babies under six months, however, the FDA and American Academy of Pediatrics recommend avoiding direct sun, using shade and protective clothing, and asking a paediatrician before applying sunscreen. The calculator therefore does not provide an estimate for this age group.
Sunscreen is only one part of sun protection
The World Health Organization recommends protective measures when the UV Index reaches 3: limit midday sun, seek shade, wear protective clothing, a hat and sunglasses, and use broad-spectrum sunscreen on uncovered skin. Sunscreen should never be used to extend time in the sun.
Frequently asked questions
How much sunscreen does the calculator use per application?
The calculator uses a fixed amount of 25 mL for every complete application.
How often does the calculator schedule a new application?
Every three hours outdoors, with the option to add extra applications after swimming, heavy sweating or towel-drying. Always follow the product directions.
How many applications are in a 200 mL bottle?
At the calculator's fixed amount of 25 mL, a 200 mL bottle corresponds to eight complete applications.
How are SunKiss applications calculated?
The total sunscreen requirement is divided by the fixed estimated amount of 30 g per dispense. Since the initial calculation is in millilitres, the equivalence assumes a density close to 1 g/mL for planning purposes; the real formulation may have a different density.
Why does the calculator not ask for height and weight?
Because it uses a fixed 25 mL amount. Height and weight would not change the result, so they have been removed to keep the calculation consistent.
Does the calculator choose an SPF?
No. It only estimates quantity. Formula and SPF choice depend on skin, UV Index, context and professional and product guidance.
Sources and methodology
- American Academy of Dermatology — How to apply sunscreen
- Cancer Council Australia — Advice on how to choose, apply and store sunscreen
- World Health Organization — Ultraviolet radiation
- U.S. Food and Drug Administration — Sunscreen and infants
- European Commission Recommendation 2006/647/EC
Calculator method: a fixed 25 mL per application and a new application every three hours, plus any extras entered by the user. Bottles are fixed at 200 mL. SunKiss applications use the fixed internal technical estimate of 30 g per dispense; equivalence with millilitres assumes, for this indicative calculation only, a density close to 1 g/mL. These are calculator planning parameters, not medical advice; product directions always take precedence.