{"id":66613,"date":"2026-10-09T14:38:46","date_gmt":"2026-10-09T11:38:46","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=66613"},"modified":"2026-10-09T14:38:46","modified_gmt":"2026-10-09T11:38:46","slug":"gas-mileage-calculator","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/life\/gas-mileage-calculator\/","title":{"rendered":"Gas Mileage Calculator"},"content":{"rendered":"<section class=\"not-prose calculator-box\" aria-labelledby=\"calculator-title\"><div class=\"flex items-baseline sm:items-center justify-between gap-2 sm:gap-3\"><div class=\"flex flex-col sm:flex-row sm:items-center gap-2\"><span class=\"icon icon-calculator text-primary-700! text-base! dark:text-primary-300!\" aria-hidden=\"true\"><\/span><h2 id=\"calculator-title\" class=\"text-lg font-display font-bold\">Calculate Your Real Fuel Economy from a Fill-Up<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"66613\" data-favorite-title=\"Gas Mileage\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/life\/gas-mileage-calculator\/\" data-favorite-excerpt=\"Calculate your real-world gas mileage (MPG, L\/100 km or km\/L) from a single fill-up. Enter the distance driven and the fuel it took to refill the tank.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-roadways\">\n    <span class=\"icon icon-shape-star-empty\" aria-hidden=\"true\"><\/span>\n  <\/button>\n  <div class=\"calcdash-favorite__tip\" aria-hidden=\"true\">\n   <span class=\"favorite-tooltip\" id=\"favorite-tooltip\"><\/span>\n  <\/div>\n  <span class=\"sr-only\" role=\"status\" id=\"favorite-status\"><\/span>\n<\/div><\/div><form action=\"https:\/\/wpcalc.com\/en\/life\/gas-mileage-calculator\/\" method=\"POST\" class=\"calculator\" id=\"calculator-66613\" data-post=\"66613\"><fieldset class=\"fieldset-input is-2\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field has-term\" id=\"input-1\"><label for=\"field-1\">Distance driven<\/label><div class=\"term\">D<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"text\" name=\"distance_driven\" id=\"field-1\" aria-describedby=\"calc-info-1\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 380\" min=\"0.1\" value=\"380\"\/><div class=\"grid grid-cols-1\"><select id=\"field-2\" name=\"unit\" aria-label=\"Unit\"><option value=\"mi\" selected>miles<\/option><option value=\"km\">kilometers<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><small id=\"calc-info-1\">Miles or km covered since the last fill-up (ideally full-to-full)<\/small><\/div><div class=\"field has-term\" id=\"input-2\"><label for=\"field-3\">Fuel used<\/label><div class=\"term\">F<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"text\" name=\"fuel_used\" id=\"field-3\" aria-describedby=\"calc-info-3\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 15.5\" min=\"0.01\" value=\"15.5\"\/><div class=\"grid grid-cols-1\"><select id=\"field-4\" name=\"unit\" aria-label=\"Unit\"><option value=\"gal\" selected>US gallons<\/option><option value=\"igal\">imp. gallons (UK)<\/option><option value=\"L\">liters<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><small id=\"calc-info-3\">Gallons or liters it took to fill the tank back up<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"66613\">Calculate<\/button><button type=\"reset\">Reset<\/button><\/div><div class=\"field is-checkbox hidden!\" id=\"field-auto-calc\"><input type=\"checkbox\" id=\"auto-calc\"><label for=\"auto-calc\">Calculate automatically<\/label><small>If enabled, the result will update automatically when you change any value.<\/small><\/div><div class=\"fieldset-result is-hidden\" aria-labelledby=\"result-title\" aria-live=\"polite\" role=\"region\"> <h3 class=\"result-title bg-gradient-to-r from-primary-50 to-gray-50 dark:from-primary-900 dark:to-gray-800\" id=\"result-title\"><span class=\"icon icon-s-pulse\" aria-hidden=\"true\"><\/span> Fuel Economy Results<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Your fuel economy<\/span><span class=\"result-term\">MPG<\/span><\/span><span class=\"field-value\" id=\"result-1\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result\" id=\"output-2\"><span class=\"field-title\"><span>Equivalent unit<\/span><span class=\"result-term\">L\/100 km<\/span><\/span><span class=\"field-value\" id=\"result-2\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result\" id=\"output-3\"><span class=\"field-title\"><span>Economy in km\/L<\/span><span class=\"result-term\">km\/L<\/span><\/span><span class=\"field-value\" id=\"result-3\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-4\"><span class=\"field-title\"><span>How it compares<\/span><\/span><span class=\"field-value\" id=\"result-4\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><\/div><div class=\"result-actions\"><button type=\"button\" class=\"copy-link\"><svg viewBox=\"0 0 20 20\" fill=\"currentColor\" aria-hidden=\"true\"><path d=\"M12.232 4.232a2.5 2.5 0 0 1 3.536 3.536l-1.225 1.224a.75.75 0 0 0 1.061 1.06l1.224-1.224a4 4 0 0 0-5.656-5.656l-3 3a4 4 0 0 0 .225 5.865.75.75 0 0 0 .977-1.138 2.5 2.5 0 0 1-.142-3.667l3-3Z\"\/><path d=\"M11.603 7.963a.75.75 0 0 0-.977 1.138 2.5 2.5 0 0 1 .142 3.667l-3 3a2.5 2.5 0 0 1-3.536-3.536l1.225-1.224a.75.75 0 0 0-1.061-1.06l-1.224 1.224a4 4 0 1 0 5.656 5.656l3-3a4 4 0 0 0-.225-5.865Z\"\/><\/svg><span class=\"copy-link__text\">Copy link to this calculation<\/span><\/button><span class=\"sr-only\" role=\"status\" id=\"copy-link-status\"><\/span><\/div><\/div><a href=\"#respond\" class=\"hidden transition-opacity duration-300 opacity-0 w-50 text-sm justify-center items-center gap-2 px-4 py-2 rounded bg-gray-200 text-gray-700 hover:bg-gray-300\" id=\"leave-comment\"><span class=\"icon icon-comments\" aria-hidden=\"true\"><\/span>Leave a Comment<\/a><\/form><\/section><section id=\"calc-reactions\" class=\"not-prose hidden my-12 bg-gradient-to-r from-primary-50 to-gray-50 border border-indigo-100 rounded-xl px-6 py-4 shadow-sm\" data-post=\"66613\" aria-live=\"polite\" aria-labelledby=\"calc-reactions-title\"><p id=\"calc-reactions-title\" class=\"text-sm text-gray-500 text-center mb-2\">How did this result make you feel?<\/p><div role=\"group\" aria-labelledby=\"calc-reactions-title\" class=\"grid grid-cols-3 sm:flex sm:flex-row sm:justify-around gap-4 sm:items-center sm:flex-wrap\"><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"like\"><span class=\"reaction-count\" data-reaction-count=\"like\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">Like <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"helpful\"><span class=\"reaction-count\" data-reaction-count=\"helpful\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">Helpful <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"confused\"><span class=\"reaction-count\" data-reaction-count=\"confused\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confused <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"disappointed\"><span class=\"reaction-count\" data-reaction-count=\"disappointed\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">Disappointed <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"inaccurate\"><span class=\"reaction-count\" data-reaction-count=\"inaccurate\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\u274c <\/span><span class=\"reaction-description font-medium\">Inaccurate <\/span><\/button><\/div><div id=\"reaction-message\" class=\"hidden mt-8 rounded-md border border-primary-100 bg-white\/50 backdrop-blur-sm px-4 py-2 text-sm text-center shadow-sm\"><\/div><\/section><div class=\"calcdash-ad not-prose calcdash-ad--calc_result calcdash-ad--in-article\"><ins class=\"adsbygoogle\" style=\"display:block\" data-ad-client=\"ca-pub-1721569815777345\" data-ad-slot=\"6317458308\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/div>\n<style id=\"wpcoderpro-inline-1\">.formula-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section class=\"formula-box\" aria-labelledby=\"formula-title\">\r\n\t<div id=\"formula-title\" class=\"not-prose font-display mb-4\"><span class=\"icon icon-formula\" aria-hidden=\"true\"><\/span><h2>Gas Mileage Formula<\/h2><\/div>\r\n\t<figure class=\"not-prose formula\">\r\n\t\t<figcaption class=\"formula-title\">Formula<\/figcaption>\r\n\t\t<div class=\"text-base text-gray-800\" id=\"formula\">\\[ \\text{Fuel economy} = \\frac{\\text{Distance driven}}{\\text{Fuel used}} \\quad \\text{(MPG or km\/L)}, \\qquad \\text{Consumption} = \\frac{\\text{Fuel used}}{\\text{Distance driven}} \\times 100 \\quad \\text{(L\/100 km)} \\\\[6pt] 1~\\text{mi} = 1.609344~\\text{km}, \\quad 1~\\text{US gal} = 3.785411784~\\text{L}, \\quad 1~\\text{imp. gal} = 4.54609~\\text{L} \\\\[6pt] \\text{MPG}_{US} = \\frac{D_{\\text{mi}}}{F_{\\text{US gal}}}, \\qquad \\text{L\/100 km} = \\frac{F_{\\text{L}}}{D_{\\text{km}}} \\times 100 \\]<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(D\\) \u2014 distance driven since the last fill-up (miles or kilometers)<\/li>\n<li>\\(F\\) \u2014 fuel needed to refill the tank (US gallons, imperial gallons or liters)<\/li>\n<\/ul>\n<p>The calculator converts your inputs to kilometers and liters, computes fuel economy in three common units, and shows the one matching your input choice first.<\/p>\n<p>\r\n<\/section>\n<style id=\"wpcoderpro-inline-459\">.calculation-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section id=\"calculation\" class=\"calculation-box\" aria-labelledby=\"calculation-title\">\r\n\t<div id=\"calculation-title\" class=\"not-prose font-display\"><span class=\"icon icon-unordered-list\" aria-hidden=\"true\"><\/span><h2>Gas Mileage \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> you filled the tank, drove 380 miles, and it took 15.5 US gallons to fill it back up.<\/p>\n<p>\\[ \\text{Distance} = 380 \\times 1.609344 = 611.55~\\text{km}, \\qquad \\text{Fuel} = 15.5 \\times 3.785411784 = 58.67~\\text{L} \\]<\/p>\n<p>\\[ \\text{MPG}_{US} = \\frac{380}{15.5} = 24.5, \\qquad \\text{L\/100 km} = \\frac{58.67}{611.55} \\times 100 = 9.6, \\qquad \\text{km\/L} = \\frac{611.55}{58.67} = 10.42 \\]<\/p>\n<p><strong>Result:<\/strong> 24.5 MPG (US) \u2014 equivalent to 9.6 L\/100 km or 10.42 km\/L. That is an average figure, typical for a mid-size petrol car in mixed driving.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to Use the Calculator<\/h2>\n<ol>\n<li>Fill your tank completely and reset the trip odometer (or write down the mileage).<\/li>\n<li>Drive as you normally would, then refill the tank to full again.<\/li>\n<li>Enter the distance covered in the <strong>Distance driven<\/strong> field and select <strong>miles<\/strong> or <strong>kilometers<\/strong> as the unit.<\/li>\n<li>Enter the amount of fuel the second fill-up required in <strong>Fuel used<\/strong>, choosing <strong>US gallons<\/strong>, <strong>imp. gallons (UK)<\/strong> or <strong>liters<\/strong>.<\/li>\n<li>Read your <strong>Your fuel economy<\/strong> result in the unit matching your input, plus the <strong>Equivalent unit<\/strong>, <strong>Economy in km\/L<\/strong> and a short comparison against typical passenger cars.<\/li>\n<\/ol>\n<h2>What Is Gas Mileage?<\/h2>\n<p>Gas mileage (also called fuel economy or fuel consumption) measures how far a vehicle travels on a given amount of fuel. In the United States and the UK it is expressed as distance per volume \u2014 miles per gallon (MPG) \u2014 where higher is better. In most other countries it is expressed as fuel used per distance, typically liters per 100 km (L\/100 km), where lower is better. The two scales are inversely related, so a car that does 24.5 MPG (US) consumes 9.6 L\/100 km.<\/p>\n<p>Be careful with gallons: a US gallon is 3.785 liters while an imperial gallon is 4.546 liters. The same car therefore shows a larger MPG figure with UK gallons \u2014 24.5 MPG (US) equals about 29.4 MPG (UK). This calculator handles both, so you can compare figures from different sources without conversion errors.<\/p>\n<p>The manufacturer's official economy rating is measured in a laboratory, so real-world results are usually 10\u201325% worse. Calculating your own figure from actual fill-ups is the only reliable way to know what your car really costs to run \u2014 and a sudden drop in mileage is often the first visible symptom of a mechanical problem, underinflated tires, or a change in driving conditions.<\/p>\n<h2>Tips for an Accurate Measurement<\/h2>\n<ul>\n<li><strong>Use the full-to-full method.<\/strong> Fill the tank to the click, drive, then fill to the click again. The fuel you add the second time equals what you burned, regardless of tank shape.<\/li>\n<li><strong>Don't trust partial fills.<\/strong> Filling from half to half, or trusting the fuel gauge, introduces large errors because tank sensors and pump shutoff points are inconsistent.<\/li>\n<li><strong>Measure over a longer distance.<\/strong> 300 miles (500 km) or more smooths out rounding at the pump; short trips give noisy results.<\/li>\n<li><strong>Compare like with like.<\/strong> Winter fuel blends, cold starts, roof racks, towing, heavy loads and city driving all lower mileage. For a fair comparison, measure over similar routes and seasons.<\/li>\n<li><strong>Track the trend, not one number.<\/strong> A single fill-up is a snapshot; a slow decline over several fill-ups is what points to maintenance issues such as dirty air filters, worn spark plugs, or low tire pressure (see the <a href=\"https:\/\/wpcalc.com\/en\/life\/tire-pressure-temperature-calculator\/\">Tire Pressure Temperature Calculator<\/a>).<\/li>\n<\/ul>\n<h2>Putting the Result to Work<\/h2>\n<p>Once you know your real fuel economy, you can estimate fuel costs for any trip: divide the trip distance by your MPG (or multiply the distance in km by L\/100 km \u00f7 100) and multiply by the fuel price. To plan where you will need to refuel on a longer journey, use the <a href=\"https:\/\/wpcalc.com\/en\/life\/road-trip-fuel-stops-calculator\/\">Road Trip Fuel Stops Calculator<\/a>, and to budget the whole trip including fuel, lodging and food, try the <a href=\"https:\/\/wpcalc.com\/en\/life\/travel-budget-calculator\/\">Travel Budget Calculator<\/a>. If you also drive for work, the <a href=\"https:\/\/wpcalc.com\/en\/life\/mileage-reimbursement-calculator\/\">Mileage Reimbursement Calculator<\/a> helps you turn those same miles into a reimbursement claim.<\/p>\n<p>If you are weighing a car against an electric alternative, remember that an EV's efficiency is measured very differently. The <a href=\"https:\/\/wpcalc.com\/en\/life\/ev-charging-cost-calculator\/\">EV Charging Cost Calculator<\/a> gives you the electricity cost per charge, which you can compare directly with your fill-up cost here.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Calculate your real-world gas mileage (MPG, L\/100 km or km\/L) from a single fill-up. Enter the distance driven and the fuel it took to refill the tank.<\/p>\n","protected":false},"author":3168,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[6],"tags":[99],"class_list":["post-66613","post","type-post","status-publish","format-standard","hentry","category-life","tag-auto-travel"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66613","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/users\/3168"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/comments?post=66613"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66613\/revisions"}],"predecessor-version":[{"id":66614,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66613\/revisions\/66614"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=66613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=66613"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=66613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}