A compass needle does not point to true north. It points along the Earth’s magnetic field, and the angle between the two is called the magnetic declination. Choose your town, or type a latitude and longitude, and this tool works out the declination for any date from 1 January 2025 to 31 December 2029 with the World Magnetic Model 2025, the model NOAA and the British Geological Survey publish. It also turns a compass bearing into a true one and says whether the correction moves it into another direction. In India the answer is small: across the 7,251 Indian towns in our town list, on 5 November 2026 it runs from 1.8 degrees west, near Kanniyakumari, to 3.0 degrees east, in Kupwara district in Jammu and Kashmir.
How it works
The World Magnetic Model describes the main magnetic field of the Earth as a set of 168 numbers for 1 January 2025, with the rate at which each one changes in a year. From those numbers, the place and the date, the tool works out the field’s direction at ground level, in your browser. The method is the one in the model’s technical report: a sum of spherical harmonics to degree and order 12, with the place turned from map coordinates into the model’s own coordinates. NOAA says of the model that its source code is in the public domain and that the information may be used freely by the public.
We checked the calculation two ways. NOAA ships 100 test values with the model, for places from 89 degrees north to 87 degrees south at heights up to 98 kilometres, and every one agrees with the tool to within 0.005 degrees of declination, which is the rounding of NOAA’s printed figures. We also asked NOAA’s own online calculator for eight places on 5 November 2026: Gondia, Waraseoni, Mumbai, Dhrangadhra, Muzaffarnagar, Lautoka in Fiji, London and New York. The tool matches it to four decimal places at all eight, for the declination, its yearly change and its uncertainty.
The town list is the same list of Indian towns our Vedic site uses for birthplaces, from GeoNames, shared under CC BY 4.0. It is read from this site, so what you type in the town box is not sent to any map service. Once your email is confirmed, what you enter and the headline of the result are kept with your email, as the note under the form says, and you can delete them at any time. For a place outside India, type the latitude and longitude, which a map app shows when you press and hold a spot.
Reading the result
The first line gives the declination to one decimal place, east or west. East means the needle points east of true north, so you add the declination to a compass bearing to get a true bearing; west means you subtract it. For Dhrangadhra on 5 November 2026 the declination is 0.72 degrees east, so a door the compass reads at 89.5 degrees is at 90.2 degrees true, still east. For New York on the same day it is 12.46 degrees west.
Below that are the yearly change, the uncertainty NOAA’s error model gives for that place, and, if you typed a bearing, the true bearing with its direction among the eight and its zone among the 16. The tool also says how far the true bearing is from the edge between two directions. A reading within ten degrees of an edge is within the error of a phone compass, so take it again from another spot.
Close to the magnetic poles the horizontal pull of the field is weak. Where it is under 2,000 nanotesla NOAA calls the area a blackout zone, in which a compass is unreliable, and up to 6,000 nanotesla a caution zone. The tool says so when your place is in either.
Where traditions differ
The classical texts do not use a magnetic compass. The Manasara, in Acharya’s summary of its sixth chapter, fixes the cardinal points with a gnomon and the sun’s shadow, as our guide to the eight directions explains, and that gives true north. So a reading corrected to true north is the closer of the two to the old method.
Our guide on finding which way your house faces calls true north the more faithful reference, while noting that in India the choice seldom changes the answer. This tool does not settle the question for you. It gives you the number, so you can see whether it matters for your home: in India it moves a reading by 3.1 degrees at most up to the end of 2029, and only a reading close to the edge of a direction changes.
What it does not do
It does not measure anything at your home. The model describes the Earth’s main field, not the pull of a steel grille, a fridge, wiring or the reinforcement in a concrete floor, which can move a needle further than the declination does. Our phone compass page explains how to take a cleaner reading, and it has a box for the declination under “Outside India? Correct for true north”.
It does not judge any direction as good or bad. It gives no forecast and makes no claim about health, money or luck. It does not use your location: the page never asks for it.
Frequently asked questions
↳ What is magnetic declination?
The angle between true north, the direction of the North Pole, and magnetic north, where a compass needle points. It changes from place to place and slowly from year to year. East declination means the needle points east of true north.
↳ How large is the declination in India?
Small. Across the 7,251 Indian towns in our list, on 5 November 2026 it runs from 1.8 degrees west near Kanniyakumari to 3.0 degrees east in Kupwara district, Jammu and Kashmir. Delhi is 1.34 degrees east and Chennai 1.07 degrees west.
↳ Do I add or subtract the declination?
Add it, with its sign. An east declination is a plus number and a west one a minus number, so true bearing equals compass bearing plus declination. If your compass app already shows true north, do not add it again.
↳ Should Vastu use true north or magnetic north?
The Manasara, as Acharya summarises it, found the directions with the sun's shadow, which gives true north, so true north is the more faithful reference. In India the two differ by 3.1 degrees at most up to the end of 2029, less than a phone compass's own error, so only a reading near the edge of a direction is affected.
↳ How accurate is the figure?
For the eight places we checked, NOAA's error model gives an uncertainty of 0.30 to 0.38 degrees. Local iron and steel can add more, which is why readings should be taken away from metal.
↳ Why can I not choose a date after 2029?
NOAA gives 31 December 2029 as the end of the World Magnetic Model 2025, and the model starts on 1 January 2025. Outside those dates the model's figures are not meant to be used, so the tool stops there.