Who provides the service
SunPosition.org is provided by the owner of the sunposition.org domain, referred to below as the Administrator. Contact: contact@sunposition.org.
Using the site means accepting these terms. If you do not accept them, please do not use the site — there is nothing to cancel, because there is no account and nothing to pay.
What the service is
SunPosition.org computes the position of the sun and the moon, sunrise and sunset times, twilight and golden hour windows, shadow lengths, solar panel angles and related figures, and draws them on a map. Everything is free, needs no account, and runs in your browser.
The service is provided as it is, without a service level agreement. The Administrator may change, suspend or withdraw any part of it, and does not promise that it will be available without interruption or free of error.
What the numbers are good for
The figures are meant for planning: where the sun will be, roughly when, and how long a shadow it will throw. Sun direction is accurate to about a hundredth of a degree and sunrise and sunset to about a minute at mid latitudes; the irradiation and yield figures are modelled, not measured.
They are not a substitute for professional advice, for a site survey, or for measured data. Do not rely on them for anything where an error would matter: navigation, aviation, safety at sea, legal boundary or right-to-light disputes, structural or electrical design, or a binding investment decision. For a bankable photovoltaic figure use PVGIS or NREL data for your address. The method page sets out exactly how each number is computed and where it stops being appropriate.
Local conditions the site cannot know — terrain, buildings, trees, weather, snow or soiling — will change the real result.
How you may use it
Use the site for your own purposes, private or professional, including using its results in your own work. You may link to any page.
Please do not:
- send automated or bulk requests that place a load on this server, or on the OpenStreetMap tile and search services it uses;
- copy the site wholesale in order to republish it;
- attempt to gain access to parts of the server that are not public, or to disrupt the service for others;
- present the results as the Administrator's professional opinion or certification.
The map tiles and place search belong to the OpenStreetMap Foundation and are subject to their own usage policies; heavy or automated use of them through this site is not permitted.
Who owns what
The design, the text and the code of this site belong to the Administrator. Map data is © OpenStreetMap contributors and is used under the Open Database Licence; the map is drawn with the Leaflet library. Astronomical formulas are, of course, nobody's property.
The numbers the site computes for you are yours to use. Quoting a page with a link back is welcome; republishing the site's text or code as your own is not.
Advertising
The site is funded by advertising served by Google AdSense. Ads load only after you agree in the cookie window, and declining costs you no functionality. The Administrator does not choose which individual ads appear and is not responsible for the goods or services they promote; what happens after you click an ad is between you and the advertiser.
What data advertising involves is described in the privacy policy.
Liability
The service is free and is provided without warranty of any kind. To the extent the law allows, the Administrator is not liable for loss arising from use of the site or from reliance on its results, nor for the availability or content of the third-party services it links to or draws on.
Nothing in these terms limits liability that cannot lawfully be limited, or the rights you have as a consumer under the mandatory law of your own country.
Problems and complaints
Found a wrong number, a broken page or something that reads as unfair? Write to contact@sunposition.org with the address of the page and what you saw. Reports about the accuracy of a result are particularly welcome and are usually answered within a few days.
Changes and applicable law
These terms may change — if the service changes, or the law does. The version in force is always the one on this page, with the date below. Continuing to use the site after a change means accepting the new version.
These terms are governed by the law applicable at the Administrator's place of establishment, without prejudice to the mandatory consumer protection of the country in which you live.
In force since 1 September 2026.