{"id":61696,"date":"2021-04-21T14:29:02","date_gmt":"2021-04-21T12:29:02","guid":{"rendered":"https:\/\/wpcalc.com\/?p=61696"},"modified":"2025-05-20T10:22:17","modified_gmt":"2025-05-20T07:22:17","slug":"free-water-deficit","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/medical\/free-water-deficit\/","title":{"rendered":"Free Water Deficit \u2013 Hypernatremia 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 class=\"text-lg font-display font-bold\">Free Water Deficit \u2013 Hypernatremia<\/h2><\/div><div class=\"relative group inline-block\">\n  <button class=\"favorite\" id=\"favorite\" data-favorite-id=\"61696\" data-favorite-title=\"Free Water Deficit \u2013 Hypernatremia \" data-favorite-url=\"https:\/\/wpcalc.com\/en\/medical\/free-water-deficit\/\" data-favorite-excerpt=\"This calculator helps determine the free water deficit in patients with hypernatremia based on their total body water (TBW) and serum sodium levels. It is useful for healthcare professionals managing dehydration and electrolyte imbalances. By selecting the patient type and entering their weight and sodium values, the tool calculates how much free water is needed to correct sodium concentration.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-pharmacology\">\n    <span class=\"icon icon-shape-star-empty\"><\/span>\n  <\/button>\n  <div class=\"absolute right-full -translate-y-1\/2 top-1\/2 mr-2 w-max max-w-xs px-3 py-2 bg-gray-800 text-white text-xs rounded shadow-lg opacity-0 group-hover:opacity-100 transition-opacity duration-200 z-10 pointer-events-none\">\n   <span class=\"favorite-tooltip\" id=\"favorite-tooltip\"><\/span>\n  <\/div>\n<\/div><\/div><form action=\"https:\/\/wpcalc.com\/en\/medical\/free-water-deficit\/\" method=\"POST\" class=\"calculator\" id=\"calculator-61696\" data-post=\"61696\"><fieldset class=\"fieldset-input is-1\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field\" id=\"input-1\"><label for=\"field-1\">Patient type<\/label><div class=\"grid grid-cols-1\"><select id=\"field-1\" name=\"patient_type\"><option value=\"1\" selected>Adult Male<\/option><option value=\"2\">Adult Female<\/option><option value=\"3\">Elderly Male<\/option><option value=\"4\">Elderly Female<\/option><option value=\"5\">Child<\/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><div class=\"field\" id=\"input-2\"><label for=\"field-2\">Weight<\/label><input type=\"number\" name=\"weight\" id=\"field-2\" placeholder=\"Weight\" step=\"any\" value=\"70\"\/><div class=\"unit\">kg<\/div><\/div><div class=\"field has-term\" id=\"input-3\"><label for=\"field-3\">Current sodium<\/label><div class=\"term\">Na<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"current_sodium\" id=\"field-3\" placeholder=\"Current Na\" step=\"any\" value=\"160\"\/><div class=\"unit\">mEq\/L<\/div><\/div><div class=\"field has-term\" id=\"input-4\"><label for=\"field-4\">Desired sodium<\/label><div class=\"term\">Na<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"desired_sodium\" id=\"field-4\" placeholder=\"Desired Na\" step=\"any\" value=\"140\"\/><div class=\"unit\">mEq\/L<\/div><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"61696\">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> Your Results<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Free water deficit:<\/span><\/span><span class=\"field-value\" id=\"result-1\"><\/span><button class=\"copy-result\" data-tooltip=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\"><\/span><\/button><\/div><\/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=\"61696\" aria-live=\"polite\"><h2 class=\"text-sm text-gray-500 text-center mb-2\">How did this result make you feel?<\/h2><div class=\"grid grid-cols-3 sm:flex sm:flex-row sm:justify-around gap-4 sm:items-center sm:flex-wrap\"><button 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\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">Like <\/span><\/button><button 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\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">Helpful <\/span><\/button><button 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\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confused <\/span><\/button><button 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\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">Disappointed <\/span><\/button><button 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\">\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><ins class=\"adsbygoogle\"\n     style=\"display:block; text-align:center; margin: 32px 0;\"\n     data-ad-layout=\"in-article\"\n     data-ad-format=\"fluid\"\n     data-ad-client=\"ca-pub-1721569815777345\"\n     data-ad-slot=\"6317458308\"><\/ins>\n<script>\n     (adsbygoogle = window.adsbygoogle || []).push({});\n<\/script>\n<p><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>Free Water Deficit 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\">$$\\text{Free Water Deficit} = TBW \\times \\left( \\frac{\\text{Current Na}}{\\text{Desired Na}} &#8211; 1 \\right)$$<\/div>\r\n\t<\/figure>\r\n\t<br \/>\n<strong>Where<\/strong>:<\/p>\n<ul>\n<li>TBW is Total Body Water (estimated from weight and patient type) <\/li>\n<li>Current Na is the current serum sodium concentration (mEq\/L)   <\/li>\n<li>Desired Na is the target serum sodium concentration, typically around 140 mEq\/L<\/li>\n<\/ul>\n<p>\r\n<\/section><br \/>\nThe Free Water Deficit is used to estimate how much water is needed to correct elevated sodium levels in cases of hypernatremia. Total Body Water (TBW) is calculated based on the patient\u2019s age, sex, and weight\u2014commonly using correction factors (e.g., 0.6 for adult males). This calculator simplifies the process for clinical use. For instance, a 70 kg adult male with a sodium level of 155 mEq\/L and a target of 140 mEq\/L would have a water deficit of approximately 7.5 liters.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This calculator helps determine the free water deficit in patients with hypernatremia based on their total body water (TBW) and serum sodium levels. It is useful for healthcare professionals managing dehydration and electrolyte imbalances. By selecting the patient type and entering their weight and sodium values, the tool calculates how much free water is needed to correct sodium concentration.<\/p>\n","protected":false},"author":70,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[8],"tags":[32],"class_list":["post-61696","post","type-post","status-publish","format-standard","hentry","category-medical","tag-pharmacology"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/61696","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\/70"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/comments?post=61696"}],"version-history":[{"count":2,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/61696\/revisions"}],"predecessor-version":[{"id":64680,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/61696\/revisions\/64680"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=61696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=61696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=61696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}