Conversion guides

Short guides that answer a common conversion question first, then show the working and a table. Every number comes from the same engine as the converters, so a guide and a converter always agree. They cover the units that most often cause confusion: Indian land measures that change from state to state, storage sizes that seem to shrink when a drive is plugged in, cup measures that weigh different amounts for different ingredients, and the lakh and crore of the Indian number system.

• Indian land measurement units explained — How big a cent, guntha, ground, acre and hectare are in square feet and square meters, where each unit is used, and why bigha, kanal and marla vary.
• Cent to square feet — One cent equals 435.6 square feet. Conversion table for 1 to 100 cents in square feet and square meters, with worked examples.
• Guntha to acre — One acre is 40 guntha, and one guntha is 1,089 square feet. Conversion table for guntha to acres, square feet and square meters.
• Ground to square feet — One ground equals 2,400 square feet in Chennai. Conversion table for grounds to square feet, square meters, cents and acres.
• GB vs GiB: decimal and binary storage units — Why a 1 TB drive shows about 931 GB in Windows: the difference between gigabytes (GB) and gibibytes (GiB), with a conversion table.
• Cups to grams by ingredient — How many grams are in a cup of flour, sugar, butter, rice, oats and other ingredients, with a table for 1 cup, ½ cup and 1 tablespoon.
• Lakh and crore in millions and billions — One lakh is 100,000 and one crore is 10 million. Conversion table between the Indian and International number systems.
• Square feet to square meters — One square foot is 0.092903 square meters and one square meter is 10.7639 square feet. Table for flat and plot sizes from 100 to 5,000 sq ft.
• Square yards (gaj) to square feet — One square yard, often called a gaj for plots in North India, equals 9 square feet. Table from 50 to 1,000 square yards in square feet and square meters.
• Acre to hectare — One acre is 0.404686 hectares and one hectare is 2.47105 acres. Conversion table for farm and plot sizes, with square meters.
• Tola to grams — One tola equals 11.6638 grams. Conversion table from 1 to 100 tola in grams and kilograms, and why a tola is not the same as 10 grams.
• AC ton to kW and BTU — A 1-ton air conditioner has 3.517 kW (12,000 BTU per hour) of cooling capacity. Table for 0.75 to 3 ton ACs, and why tonnage is not power consumption.
• Electricity units (kWh) explained — One unit on an electricity bill is one kilowatt-hour. How to work out units from watts and hours, with a table of monthly units for common wattages.