Any INCI list or US Drug Facts panel. It stays in this tab and is sent nowhere. We take it apart into its molecules, mark the ones we make, and rebuild it with Sunbest filters for the same SPF.
{{ g.title }}
{{ g.sub }}Ceilings are indicative for the selected market and clamp every slider; a greyed row is not a permitted filter there, or not one we could verify on that market's list. A dagger marks a ceiling with a condition attached, listed below. Always verify against the current annex before you file.
{{ fromText }}
± 20% in-silico band; wider for mineral decks. Label claims need ISO 24444 and ISO 24443 at a test house; we can arrange both.
The spectrum you just built
Stacked absorbance per filter across 290–400 nm. The dashed line is the same deck after its UVA dose of 1.2 J/cm² per unit of initial UVA-PF, the ISO 24443 exposure rule. The gap between the two is photoinstability. The vertical mark is the critical wavelength of the irradiated film; it must sit at 370 nm or beyond for broad-spectrum claims.
Work backwards from the claim
Name the protection you need and the engine searches the Sunbest range under the ceilings of your market. It returns the most efficient deck, a photostable deck without avobenzone and a mineral route. Treat each as a starting point for a formula.
Method and sources
Each filter carries a reconstructed extinction spectrum anchored to its published peak wavelength and specific extinction E(1,1). A sunscreen film is never the uniform 20 µm the labelled 2 mg/cm² implies (it pools and thins over skin texture), so transmission is computed over a gamma distribution of film heights, the continuous-height model of the open literature (O'Neill 1984; Herzog 2002; Ferrero et al. 2003; Herzog & Osterwalder 2015), with the shape parameter anchored so that 10% ethylhexyl methoxycinnamate alone lands at its in-vivo SPF of about 11.
The protection factors then follow the ISO 24443 algorithm with the measured transmission replaced by the calculated one. SPF weights transmission by the CIE-1987 erythema action spectrum and the UV solar-simulator spectrum; UVA-PF weights it by the persistent-pigment-darkening action spectrum and the UVA source spectrum, 320–400 nm. All four are the 1 nm tables of ISO 24443 Appendix I. The initial UVA-PF sets the exposure, 1.2 J/cm² of UVA per unit, and UVA-PF, critical wavelength and the UVA:UVB ratio are then read from the irradiated film, as the standard reads them from the irradiated plate. SPF is shown for the initial film, the in-vitro form, and after that dose.
Photostability is first-order in dose, from the retained-absorbance values we measured on our own filters where they exist. Those measurements do not state their dose, so the engine assumes they correspond to 12 J/cm² of UVA, the ISO dose of a UVA-PF 10 product, and scales from there. That is an assumption, stated here so nobody has to guess. Two interactions are modelled on top: avobenzone decaying faster next to ethylhexyl methoxycinnamate, and being rescued by triplet quenchers like octocrylene. The film former SunBoost-PHS raises protection not by absorbing anything but by evening the film, which is exactly how the model treats it. Mineral filters carry empirical, grade-dependent attenuation shapes rather than a molecular spectrum, so their band is the widest.
The UVA:UVB ratio is the mean absorbance over 320–400 nm divided by the mean over 290–320 nm on the irradiated film; the bands shown (≥ 0.6, ≥ 0.8, ≥ 0.9) are the conventional ratio thresholds, offered as orientation rather than as any rating scheme's result. The EU checks are the Commission Recommendation 2006/647/EC pair: UVA-PF at least a third of SPF, and critical wavelength at 370 nm or beyond.
Ceilings were reconciled with the 2026-09-08 dosage audit of the whole catalogue. Where a market's list could not be verified for a filter, the row is greyed and says so rather than asserting a number.
This is an independent implementation written from the published literature and public standards; it is not derived from, affiliated with, or endorsed by any commercial sunscreen-simulation software. Every number here is an in-silico estimate for formulation design. It is not a claim, a test report, or regulatory advice; label SPF and UVA-PF come from ISO 24444 and ISO 24443 at an accredited test house, and permitted-use limits from the current annex of your market. Send us the deck and we take it from there.