# SPF Guide
> An independent UK consumer buyer's guide to sun protection, published by Northbank Media. We score sunscreen FORMULATION CATEGORIES out of 100 against published testing standards and public evidence. We do not name, rank, test or recommend individual products, brands or retailers, and no company can buy, influence or preview a score. No affiliate commission is taken on sunscreen sales.

## What a score means
A score rates a category of formulation, for example a high load zinc oxide cream or an alcohol driven aerosol spray. It is built from five weighted criteria: broad spectrum evidence (25), realistic dose delivery (25), wear and reapplication (20), tolerability (15) and label transparency (15). It is never applied to a named product.

## What this site does not do
No product names. No brand names. No affiliate links. No sponsored content. No paid placement. No own laboratory testing, and no implication that we run any. Nothing here is medical advice.

## Category reviews, with headline scores
- /best/mineral-sunscreens (82/100): Mineral sunscreens use zinc oxide, titanium dioxide or both as the only UV filters. As a category they score 82 out of 100 in our framework: excellent tolerability and immediate protection on application, held back by the fact that a cosmetically pleasant mineral texture usually means a lower filter load, and that people apply thin layers of anything that feels heavy. A zinc oxide cream at a high filter load is the strongest mineral format we score. Brush-on mineral powder is the weakest, because the dose reaching the skin is a small fraction of what any SPF test uses.
- /best/chemical-sunscreens (88/100): Chemical sunscreens use organic UV filters, which absorb ultraviolet energy and release it as heat. As a category they score 88 out of 100, the highest on this site, because the filter systems permitted in the UK deliver better UVA coverage per unit of product than mineral filters and do it in textures people apply generously. The score is an average across very different formulations. A modern broad spectrum filter fluid earns 90. An alcohol driven aerosol spray earns 66, because the dose that lands on skin is unpredictable and usually too thin.
- /best/sunscreen-for-sensitive-skin (84/100): For reactive skin the best scoring category is a fragrance free zinc oxide cream at 88 out of 100, with fragrance free hybrid and organic filter fluids close behind at 82 and 78. The category average is 84. The strongest finding across the evidence is that most sunscreen reactions are not caused by the UV filters at all. Fragrance, certain preservatives and, in a smaller number of cases, specific organic filters account for the majority of confirmed reactions. A product marketed for sensitive skin but carrying a fragrance load scores 58, below several products that make no sensitivity claim.
- /best/water-resistant-sunscreen (85/100): Water resistant is a tested claim, not a marketing phrase. To carry it, a formulation must retain at least half of its labelled SPF after two twenty minute immersions in water. Very water resistant requires the same after four immersions, which is where the eighty minute figure comes from. As a category, water resistant formulations score 85 out of 100. A very water resistant organic filter emulsion earns 88, the strongest performer. Sprays sold for sport earn 60, because the claim is tested on a full applied film and a spray rarely delivers one.
- /best/sunscreen-for-dark-skin-tones (86/100): For deep skin tones the highest scoring formulation is a tinted hybrid fluid containing iron oxides, at 90 out of 100, because it adds visible light protection without leaving a grey cast. Clear organic filter fluids follow at 86. An untinted high load zinc oxide cream scores 62, not because it fails at UV but because a visible ash finish means it will not be worn, and a sunscreen nobody wears protects nobody. Visible light, not just UV, drives melasma and post inflammatory hyperpigmentation in melanin rich skin, which is why the tint is doing protective work rather than cosmetic work.
- /best/face-sunscreen-under-makeup (83/100): The best scoring format for wearing under makeup is a light organic filter fluid at 88 out of 100, because it sets quickly, does not pill under a base and is applied generously enough to approach a useful dose. The category scores 83 overall. The lowest score on this page, 40, goes to relying on the SPF built into foundation or powder as your only protection. Those products are tested at the same dose as any sunscreen, and nobody applies foundation at that thickness. Treat cosmetic SPF as a small bonus on top of a real one.
- /best/kids-sunscreen (84/100): The best scoring format for children is a fragrance free high zinc cream at 88 out of 100, closely followed by a very water resistant SPF 50 kids' lotion at 86. The category averages 84. Aerosol sprays score 58 and are the format most likely to leave a child burnt, because the delivered dose is thin, uneven and lost to the wind. UK guidance from the NHS and Cancer Research UK is consistent on the order of priorities: shade between eleven and three, clothing and a hat, then sunscreen at SPF 30 or above with a high UVA rating. Babies under six months should be kept out of direct sun entirely.
- /best/sport-and-outdoor-sunscreen (82/100): For sport and long outdoor days the strongest formulation is a very water resistant emulsion at 88 out of 100, because it resists both sweat sheeting and the friction of clothing and kit. Sticks score 82 and are the best answer for noses, ears and cheekbones where sweat runs. The category averages 82. Aerosol sprays score 60 for the same reason they do elsewhere: convenience does not produce a film thick enough to match the tested claim. Altitude and reflection raise exposure sharply, which is why hill and snow days need the same discipline as a beach.

## Explainers
- /learn/how-spf-is-tested: SPF is measured by applying a sunscreen at exactly two milligrams per square centimetre to the backs of human volunteers, exposing patches of protected and unprotected skin to a solar simulator, and comparing how much energy each needs to turn faintly pink. The ratio is the sun protection factor. It is a real, repeatable measurement, and it describes UVB protection only, at a dose thicker than almost anyone applies. That is why an SPF 50 bottle typically behaves like something between SPF 10 and SPF 25 in ordinary use.
- /learn/uva-vs-uvb-and-what-pa-means: UVB is the shorter wavelength band that burns skin and drives most non melanoma skin cancer. UVA is the longer band that penetrates deeper, passes through window glass, causes photoageing and contributes to pigmentation. SPF rates UVB only. UVA protection in the UK is shown either by the UVA in a circle mark, meaning UVA protection is at least a third of the SPF, or by a star rating out of five. The Japanese PA system, seen on imported products, uses plus signs based on a different measurement of persistent pigment darkening. A UK pack with SPF 50 and the circled UVA mark is broadly comparable to PA++++.
- /learn/how-much-sunscreen-to-actually-apply: A full adult body needs around thirty five millilitres of sunscreen for a single application, which is roughly six to seven teaspoons: one for the face and neck, one for each arm, one for each leg, one for the chest and abdomen and one for the back. For the face alone, the two finger rule is the practical measure: a line of product along the length of your index and middle fingers. Published measurements show most people apply between a quarter and a half of this, and the loss of protection is disproportionately large rather than proportional.
- /learn/does-sunscreen-expire: Yes, sunscreen expires. UK cosmetic rules require an expiry date on any product with a shelf life under thirty months, and a period after opening symbol, shown as an open jar with a number of months, on products that last longer. In practice most sunscreens carry twelve month period after opening marks. The bigger risk is heat rather than time: a bottle left in a hot car or in direct sun for a summer may have degraded well before its printed date. Separation, a changed smell, grittiness or a watery layer are all reasons to throw it away.
- /learn/reef-safe-sunscreen-claims-examined: Reef safe has no legal definition, no certification body and no agreed testing standard in the UK. Any product may carry the phrase. The research behind it is genuine but contested: laboratory work has shown harm to coral from certain UV filters at particular concentrations, while the environmental relevance of those concentrations is disputed. Several destinations, including Hawaii, Palau and Bonaire, have restricted named filters by law. If a specific destination has rules, follow them. Otherwise treat the phrase as marketing and read the filter list instead.
- /learn/vitamin-d-and-sunscreen: Studies of real world sunscreen use have not found it to cause vitamin D deficiency. Even careful application leaves gaps, sunscreen is applied thinner than the test dose, and the amount of ultraviolet needed to make vitamin D is far smaller than the amount needed to burn. The much larger factor in the UK is latitude. Between roughly October and March, sunlight across the whole of the UK is too weak in UVB for the skin to make vitamin D at all, whatever you do or do not put on it. NHS guidance recommends a daily ten microgram supplement through autumn and winter, and year round for people with limited sun exposure or deeper skin tones.

## Guide pages
- /method: the five weighted criteria, the score bands, the evidence base and the funding position
- /about: who publishes the guide, why it scores categories rather than products, and what it refuses to do
- /contact: corrections, questions about a score and category requests

## Sources we rely on
Published international testing standards for SPF, UVA and water resistance; the UK permitted UV filter list and its concentration limits; European scientific committee safety opinions; peer reviewed literature on photostability, contact and photocontact allergy and visible light pigmentation; and public guidance from the NHS, the British Association of Dermatologists, Cancer Research UK, the British Skin Foundation and the World Health Organization.

Last reviewed 2026-07-31.