{"scale":"1:20,000","standard":"USGS","series":"Puerto Rico 7.5 minute","actual_ft":0.0006,"actual_ft_unit":"in","scale_in":1670,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":200,"scale_cm_unit":"m","scale_cm_accuracy":"exact","size_latlon":"7.5 by 7.5 minute","size_latlon_unit":"minute","area_approx":"7.10E+01","area_approx_unit":"sq mi"}
{"scale":"1:24,000","standard":"USGS","series":"7.5 minute","actual_ft":0.0005,"actual_ft_unit":"in","scale_in":2000,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":240,"scale_cm_unit":"m","scale_cm_accuracy":"exact","size_latlon":"7.5 by 7.5 minute","size_latlon_unit":"minute","area_approx":"49 to 70","area_approx_unit":"sq mi"}
{"scale":"1:25,000","standard":"USGS","series":"7.5 minute","actual_ft":0.00048,"actual_ft_unit":"in","scale_in":2080,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":250,"scale_cm_unit":"m","scale_cm_accuracy":"exact","size_latlon":"7.5 by 7.5 minute","size_latlon_unit":"minute","area_approx":"49 to 70","area_approx_unit":"sq mi"}
{"scale":"1:25,000","standard":"USGS","series":"7.5 by 15 minute","actual_ft":0.00048,"actual_ft_unit":"in","scale_in":2080,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":250,"scale_cm_unit":"m","scale_cm_accuracy":"exact","size_latlon":"7.5 by 15 minute","size_latlon_unit":"minute","area_approx":"98 to 140","area_approx_unit":"sq mi"}
{"scale":"1:50,000","standard":"USGS","series":"USGS-DMA 15 minute","actual_ft":0.00024,"actual_ft_unit":"in","scale_in":4170,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":500,"scale_cm_unit":"m","scale_cm_accuracy":"exact","size_latlon":"15 by 15 minute","size_latlon_unit":"minute","area_approx":"197 to 282","area_approx_unit":"sq mi"}
{"scale":"1:62,500","standard":"USGS","series":"15 minute*","scale_in":1,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":625,"scale_cm_unit":"m","scale_cm_accuracy":"exact","size_latlon":"15 by 15 minute","size_latlon_unit":"minute","area_approx":"197 to 282","area_approx_unit":"sq mi","series_status":"abandoned"}
{"scale":"1:63,360","standard":"USGS","series":"Alaska Maps","scale_in":1,"scale_in_unit":"mi","scale_in_accuracy":"exact","scale_cm":634,"scale_cm_unit":"m","scale_cm_accuracy":"exact","size_latlon":"15 by 20 to 36 minute","size_latlon_unit":"minute","area_approx":"207 to 281","area_approx_unit":"sq mi"}
{"scale":"1:50,000","standard":"USGS","series":"County Maps","actual_ft":0.00024,"actual_ft_unit":"in","scale_in":4170,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":500,"scale_cm_unit":"m","scale_cm_accuracy":"exact","size_latlon":"County area","area_approx":"Varies"}
{"scale":"1:100,000","standard":"USGS","series":"County Maps","scale_in":1.6,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":1,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"County area","area_approx":"Varies"}
{"scale":"1:100,000","standard":"USGS","series":"30 by 60 minute","scale_in":1.6,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":1,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"30 by 60 minute","size_latlon_unit":"minute","area_approx":"1,568 to 2,240","area_approx_unit":"sq mi"}
{"scale":"1:125,000","standard":"USGS","series":"30 minute*","scale_in":2,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":1.25,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"30 by 30 minute","size_latlon_unit":"minute","area_approx":"786 to 1,124","area_approx_unit":"sq mi","series_status":"abandoned"}
{"scale":"1:250,000","standard":"USGS","series":"1 degree by 2 degrees or 3 degrees","scale_in":4,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":2.5,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"1° by 2° or 3°","size_latlon_unit":"degree","area_approx":"4,580 to 8,669","area_approx_unit":"sq mi"}
{"scale":"1:500,000","standard":"USGS","series":"State Maps","scale_in":8,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":5,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"State area","area_approx":"Varies"}
{"scale":"1:1,000,000","standard":"USGS","series":"State Maps","scale_in":16,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":10,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"State area","area_approx":"Varies"}
{"scale":"1:2,000,000","standard":"USGS","series":"U.S. Sectional Maps","scale_in":32,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":20,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"State groups","area_approx":"Varies"}
{"scale":"1:250,000","standard":"USGS","series":"Antarctica Maps","scale_in":4,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":2.5,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"1° by 3° to 15°","size_latlon_unit":"degree","area_approx":"4,089 to 8,336","area_approx_unit":"sq mi"}
{"scale":"1:500,000","standard":"USGS","series":"Antarctica Maps","scale_in":8,"scale_in_unit":"mi","scale_in_accuracy":"approximate","scale_cm":5,"scale_cm_unit":"km","scale_cm_accuracy":"exact","size_latlon":"2° by 7.5°","size_latlon_unit":"degree","area_approx":"28,174 to 30,462","area_approx_unit":"sq mi"}
{"scale":"1 in = 10 feet","standard":"Engineering","actual_ft":0.1,"actual_ft_unit":"in","scale_in":10,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":3.05,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1 in = 20 feet","standard":"Engineering","actual_ft":0.05,"actual_ft_unit":"in","scale_in":20,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":6.1,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1 in = 30 feet","standard":"Engineering","actual_ft":0.0333,"actual_ft_unit":"in","scale_in":30,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":9.14,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1 in = 40 feet","standard":"Engineering","actual_ft":0.025,"actual_ft_unit":"in","scale_in":40,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":12.2,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1 in = 50 feet","standard":"Engineering","actual_ft":0.02,"actual_ft_unit":"in","scale_in":50,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":15.2,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1 in = 60 feet","standard":"Engineering","actual_ft":0.0167,"actual_ft_unit":"in","scale_in":60,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":18.3,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"3/32 in = 1 foot","standard":"Architectural","actual_ft":0.0938,"actual_ft_unit":"in","scale_in":10.7,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":3.25,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"3/16 in = 1 foot","standard":"Architectural","actual_ft":0.188,"actual_ft_unit":"in","scale_in":5.33,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":1.63,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1/8 in = 1 foot","standard":"Architectural","actual_ft":0.125,"actual_ft_unit":"in","scale_in":8,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":2.44,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1/4 in = 1 foot","standard":"Architectural","actual_ft":0.25,"actual_ft_unit":"in","scale_in":4,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":1.22,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"3/8 in = 1 foot","standard":"Architectural","actual_ft":0.375,"actual_ft_unit":"in","scale_in":2.67,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":0.813,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1/2 in = 1 foot","standard":"Architectural","actual_ft":0.5,"actual_ft_unit":"in","scale_in":2,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":0.61,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"3/4 in = 1 foot","standard":"Architectural","actual_ft":0.75,"actual_ft_unit":"in","scale_in":1.33,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":0.406,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1 in = 1 foot","standard":"Architectural","actual_ft":1,"actual_ft_unit":"in","scale_in":1,"scale_in_unit":"ft","scale_in_accuracy":"exact","scale_cm":0.305,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1½ in = 1 foot","standard":"Architectural","actual_ft":1.5,"actual_ft_unit":"in","scale_in":0.667,"scale_in_unit":"ft","scale_in_accuracy":"approximate","scale_cm":0.203,"scale_cm_unit":"m","scale_cm_accuracy":"approximate","series_status":"common"}
{"scale":"1:5,000","standard":"British military","series":"Local operations maps, used for similar purposes to the trench maps","scale_in":0.08,"scale_in_unit":"mi","scale_in_accuracy":"exact","scale_cm":24.4,"scale_cm_unit":"km","scale_cm_accuracy":"approximate"}
{"scale":"1:10,000","standard":"British military","series":"Trench maps, used for patrols and raids at a local level","scale_in":0.16,"scale_in_unit":"mi","scale_in_accuracy":"exact","scale_cm":48.8,"scale_cm_unit":"km","scale_cm_accuracy":"approximate"}
{"scale":"1:20,000","standard":"British military","series":"Heavy/Medium artillery maps, used as a precise locational aid for pinpointing particular targets","scale_in":0.31,"scale_in_unit":"mi","scale_in_accuracy":"exact","scale_cm":94.5,"scale_cm_unit":"km","scale_cm_accuracy":"approximate"}
{"scale":"1:40,000","standard":"British military","series":"Administration maps","scale_in":0.63,"scale_in_unit":"mi","scale_in_accuracy":"exact","scale_cm":192,"scale_cm_unit":"km","scale_cm_accuracy":"approximate"}