When I first started to show and sell my work my pricing was just all over the map! I scrambled to make sense of putting a dollar value on my art and then making sure that the prices made sense as the work scaled up and down in size. In the past I have talked to other artists as I tried to sort through ideas on pricing and received different opinions: the work is priced too high, the work is priced too low. But there were a few artists who priced by the square inch which helped them to create consistency between sizes.
I think the most important thing about pricing your art work is to work out your prices carefully, have a system for pricing different sizes and once that's done, don't waffle on the price. Then as you grow in your career you can increase your prices. I like to look back to two years ago and make sure that my prices have increased since then, as I know how much I have worked and achieved since that time. When potential buyers are visiting your website, your pricing structure show make sense and communicate why some works are priced higher or lower than others. Size is an easy indicator to understand.
Here is the practical approach to pricing per square inch from the blog of Chris Tyrell Loranger author of Artist Survival Skills and Making It:
Prices per Square Inch: A “price-per-square-inch” pricing system can sound too “industrial” or “commercial” to some artists at first, but it is a logical and proven method that guarantees price coherence and stability through a career as well as ongoing customer satisfaction. To calculate the price-per-square-inch of a work of art is simple: you multiply the length of the piece by its width to get the number of square inches, and then you divide the price of the piece by the number of square inches. (You can also use united inches instead of square inches.)
[ Height ] + [ Width ] = United Inches
[ Height ] X [ Width ] = Square Inches
(Retail or full) Price, divided by the number of square inches = the price-per-square-inch
(Retail or full) Price, divided by the number of united inches = the price-per-united-inch
*Please note that if you create small and large works you will need to tweak the cost per united inch otherwise the smallest works will be too cheap or the largest works will be too expensive.
Before trying the price per square inch approach you might need to establish a realistic price per square inch for at least one size of the art you make. The best way to do this is by comparison, find ten artists who work in roughly the same size, are in the same place in their art career and have the same quality of work as you. Find out the price of a piece by each of these artists and then work backwards to figure out what their united inch is. Take these 10 numbers, add them and divide them by ten to get the average. The average that you have come up with can be a place for you to start calculating your price per square inch. See what numbers you come up with and if they are both in-line with your income expectations for selling and affordable for your market.