{"id":100150,"date":"2026-02-15T20:21:10","date_gmt":"2026-02-15T20:21:10","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100150"},"modified":"2026-07-12T19:58:34","modified_gmt":"2026-07-12T19:58:34","slug":"mass-weight-converter","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/sk\/calculators\/mass-weight-converter\/","title":{"rendered":"Mass Unit Converter"},"content":{"rendered":"\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Mass Unit Converter\",\"description\":\"Convert non-negative mass values between SI,avoirdupois,troy and selected customary units using documented exact definitions and explicit mass-versus-weight boundaries.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/mass-weight-converter\/\",\"applicationCategory\":\"Engineering Reference\",\"operatingSystem\":\"Any\",\"offers\":{\"@type\":\"Offer\",\"price\":\"0\",\"priceCurrency\":\"EUR\"},\"creator\":{\"@type\":\"Organization\",\"name\":\"Vibromera\",\"url\":\"https:\/\/vibromera.eu\/\"},\"dateModified\":\"2026-07-12\",\"inLanguage\":\"en\",\"isAccessibleForFree\":true}<\/script>\n<style>:root{--mu:#704d9a;--mul:#f2edf8;--ink:#181817;--sec:#595750;--mut:#817e76;--b:#d8d4cc;--bl:#e9e5dd;--alt:#f8f6f1;--red:#b42318;--yel:#fff8df;--amb:#8a6500;--font:'DM Sans',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif}.mu-wrap{font-family:var(--font);color:var(--ink);max-width:1060px;margin:0 auto;border:1px solid var(--bl);border-radius:16px;overflow:hidden;background:#fff}.mu-wrap *,.mu-wrap *:before,.mu-wrap *:after{box-sizing:border-box}.mu-hero{padding:34px 38px 26px;background:linear-gradient(135deg,#faf8fc,#f3eef8)}.mu-kicker{text-transform:uppercase;letter-spacing:.1em;font-size:12px;font-weight:800;color:var(--mu)}.mu-hero h1{font-size:clamp(28px,4vw,44px);line-height:1.08;margin:8px 0 12px}.mu-lead{font-size:17px;line-height:1.65;color:var(--sec);max-width:920px}.mu-badges{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}.mu-badge{padding:6px 10px;border-radius:99px;background:#fff;border:1px solid var(--b);font-size:12px;font-weight:700}.mu-main{padding:30px 38px}.mu-panel{border:1px solid var(--b);border-radius:14px;padding:24px}.mu-panel h2{font-size:22px;margin:0 0 8px}.mu-note{font-size:14px;line-height:1.55;color:var(--sec)}.mu-grid{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-top:20px}.mu-field{display:flex;flex-direction:column;gap:7px}.mu-label{font-size:13px;font-weight:800}.mu-help{font-size:12px;line-height:1.4;color:var(--mut)}.mu-input,.mu-select{font:inherit;width:100%;border:1px solid #bcb8af;border-radius:9px;padding:11px 12px;background:#fff;color:var(--ink)}.mu-input:focus,.mu-select:focus{outline:3px solid rgba(112,77,154,.17);border-color:var(--mu)}.mu-error{min-height:22px;color:var(--red);font-size:14px;font-weight:800;margin:14px 0 0}.mu-results{margin-top:20px;border:1px solid var(--b);border-radius:12px;overflow:hidden}.mu-results[hidden]{display:none}.mu-rhead{background:var(--mul);padding:18px 20px}.mu-rtitle{font-size:20px;font-weight:900;color:var(--mu)}.mu-rsub{font-size:13px;color:var(--sec);margin-top:4px}.mu-rgrid{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--bl)}.mu-card{background:#fff;padding:18px}.mu-card h3{font-size:12px;text-transform:uppercase;letter-spacing:.06em;color:var(--mut);margin:0 0 8px}.mu-val{font-size:18px;font-weight:900;overflow-wrap:anywhere}.mu-unit{font-size:12px;color:var(--mut);margin-top:4px}.mu-alert{border-left:4px solid var(--amb);background:var(--yel);padding:14px 16px;margin-top:18px;font-size:14px;line-height:1.55}.mu-section{border-top:1px solid var(--bl);padding:28px 38px}.mu-section h2{font-size:24px;margin:0 0 10px}.mu-section h3{font-size:18px;margin:22px 0 8px}.mu-section p,.mu-section li{font-size:14px;line-height:1.65;color:var(--sec)}.mu-table-wrap{overflow-x:auto;border:1px solid var(--b);border-radius:10px}.mu-table{width:100%;border-collapse:collapse;min-width:760px}.mu-table th,.mu-table td{padding:12px 13px;text-align:left;vertical-align:top;border-bottom:1px solid var(--bl);font-size:13px;line-height:1.45}.mu-table th{background:var(--alt);font-weight:900}.mu-table tr:last-child td{border-bottom:0}.mu-code{font-family:ui-monospace,SFMono-Regular,Consolas,monospace}.mu-footer{padding:20px 38px;background:var(--alt);font-size:12px;color:var(--mut)}.mu-footer a,.mu-section a{color:var(--mu)}@media(max-width:700px){.mu-hero,.mu-main,.mu-section{padding-left:20px;padding-right:20px}.mu-grid,.mu-rgrid{grid-template-columns:1fr}.mu-panel{padding:18px}.mu-table{min-width:680px}}<\/style>\n<div class=\"mu-wrap\"><header class=\"mu-hero\"><div class=\"mu-kicker\">Mass units \u00b7 not force or weight-force<\/div><h1>Mass Unit Converter<\/h1><p class=\"mu-lead\">Convert a non-negative mass between SI units,avoirdupois units,troy ounce,grain,stone and explicitly identified short and long tons. Every customary unit is named to prevent ounce,pound and ton ambiguity.<\/p><div class=\"mu-badges\"><span class=\"mu-badge\">Exact defined factors<\/span><span class=\"mu-badge\">Avoirdupois and troy separated<\/span><span class=\"mu-badge\">Decimal point or comma<\/span><span class=\"mu-badge\">No mass-to-force assumption<\/span><\/div><\/header>\n<main class=\"mu-main\"><section class=\"mu-panel\"><h2>Convert one mass value<\/h2><p class=\"mu-note\">Select the unit that actually accompanies the source value. Changing the unit selector reinterprets\u2014not converts\u2014the number already entered.<\/p><form id=\"mu-form\" novalidate><div class=\"mu-grid\"><div class=\"mu-field\"><label class=\"mu-label\" for=\"mu-value\">Non-negative mass value<\/label><input class=\"mu-input\" id=\"mu-value\" inputmode=\"decimal\" autocomplete=\"off\"><span class=\"mu-help\">Enter one complete finite number;scientific notation is accepted.<\/span><\/div><div class=\"mu-field\"><label class=\"mu-label\" for=\"mu-unit\">Input mass unit<\/label><select class=\"mu-select\" id=\"mu-unit\"><option value=\"\">Select\u2026<\/option><option value=\"mg\">milligram (mg)<\/option><option value=\"g\">gram (g)<\/option><option value=\"kg\">kilogram (kg)<\/option><option value=\"tonne\">tonne (t;metric ton)<\/option><option value=\"grain\">grain (gr)<\/option><option value=\"oz_av\">ounce avoirdupois (oz av)<\/option><option value=\"lb_av\">pound avoirdupois (lb av)<\/option><option value=\"stone\">stone (st;14 lb av)<\/option><option value=\"short_ton\">short ton (US;2000 lb av)<\/option><option value=\"long_ton\">long ton (Imperial;2240 lb av)<\/option><option value=\"troy_oz\">troy ounce (oz t;480 gr)<\/option><option value=\"carat\">carat (ct)<\/option><\/select><\/div><\/div><p class=\"mu-error\" id=\"mu-error\" role=\"alert\"><\/p><\/form>\n<section class=\"mu-results\" id=\"mu-results\" hidden data-json=\"\"><div class=\"mu-rhead\"><div class=\"mu-rtitle\">Equivalent mass values<\/div><div class=\"mu-rsub\" id=\"mu-summary\">\u2014<\/div><\/div><div class=\"mu-rgrid\" id=\"mu-rgrid\"><\/div><\/section>\n<div class=\"mu-alert\"><strong>Quantity boundary:<\/strong> these are mass units. In science and engineering,weight is a force and its SI unit is the newton. Converting mass to weight-force requires an explicitly chosen acceleration of free fall;this page does not assume local or standard gravity.<\/div><\/section><\/main>\n<section class=\"mu-section\"><h2>Definitions used by the calculator<\/h2><div class=\"mu-table-wrap\"><table class=\"mu-table\"><thead><tr><th>Unit<\/th><th>Exact kilograms used<\/th><th>Definition or identity<\/th><\/tr><\/thead><tbody><tr><td>milligram (mg)<\/td><td class=\"mu-code\">0.000001kg<\/td><td>SI prefix relation<\/td><\/tr><tr><td>gram (g)<\/td><td class=\"mu-code\">0.001kg<\/td><td>SI prefix relation<\/td><\/tr><tr><td>kilogram (kg)<\/td><td class=\"mu-code\">1kg<\/td><td>SI base unit of mass<\/td><\/tr><tr><td>tonne (t)<\/td><td class=\"mu-code\">1000kg<\/td><td>metric ton<\/td><\/tr><tr><td>grain (gr)<\/td><td class=\"mu-code\">0.00006479891kg<\/td><td>1\/7000 avoirdupois pound<\/td><\/tr><tr><td>ounce avoirdupois (oz av)<\/td><td class=\"mu-code\">0.028349523125kg<\/td><td>1\/16 avoirdupois pound<\/td><\/tr><tr><td>pound avoirdupois (lb av)<\/td><td class=\"mu-code\">0.45359237kg<\/td><td>international pound<\/td><\/tr><tr><td>stone (st)<\/td><td class=\"mu-code\">6.35029318kg<\/td><td>14 avoirdupois pounds<\/td><\/tr><tr><td>short ton<\/td><td class=\"mu-code\">907.18474kg<\/td><td>2000 avoirdupois pounds<\/td><\/tr><tr><td>long ton<\/td><td class=\"mu-code\">1016.0469088kg<\/td><td>2240 avoirdupois pounds<\/td><\/tr><tr><td>troy ounce (oz t)<\/td><td class=\"mu-code\">0.0311034768kg<\/td><td>480 grains;not an avoirdupois or fluid ounce<\/td><\/tr><tr><td>carat (ct)<\/td><td class=\"mu-code\">0.0002kg<\/td><td>200mg<\/td><\/tr><\/tbody><\/table><\/div><p>The calculation first converts the input to kilograms,then divides by each listed kilograms-per-unit factor. Display values are rounded to at most12 significant digits;the machine-readable result retains the JavaScript numerical value. Do not infer measurement uncertainty or additional significant figures from a unit conversion.<\/p><\/section>\n<section class=\"mu-section\"><h2>Sources and standards status<\/h2><p><a href=\"https:\/\/www.bipm.org\/en\/publications\/si-brochure\/\" target=\"_blank\" rel=\"noopener\">BIPM,The International System of Units (SI),9th edition (2019),updated2026<\/a> is the current SI reference. <a href=\"https:\/\/www.nist.gov\/pml\/special-publication-811\/nist-guide-si-appendix-b-conversion-factors\/nist-guide-si-appendix-b8\" target=\"_blank\" rel=\"noopener\">NIST SP811 Appendix B.8<\/a> lists conversion factors for grain,avoirdupois and troy ounce,long ton,short ton and tonne;NIST&#8217;s footnotes identify the international avoirdupois pound as exactly0.45359237kg.<\/p><p><a href=\"https:\/\/www.nist.gov\/pml\/owm\/si-units-mass\" target=\"_blank\" rel=\"noopener\">NIST&#8217;s mass guidance<\/a> distinguishes mass from weight-force and states that the SI unit of weight in science and technology is the newton. Standard gravity <span class=\"mu-code\">g<sub>n<\/sub>=9.80665m\/s\u00b2<\/span> is an exact conventional value only when expressly selected;local gravity varies.<\/p><h3>Balancing terminology correction<\/h3><p>The former FAQ cited \u201cISO1940\u201d as though it were current and described g\u00b7mm\/kg as permissible residual unbalance. ISO&#8217;s official lifecycle records show <a href=\"https:\/\/www.iso.org\/standard\/27092.html\" target=\"_blank\" rel=\"noopener\">ISO1940-1:2003 is withdrawn<\/a> and revised by <a href=\"https:\/\/www.iso.org\/standard\/54074.html\" target=\"_blank\" rel=\"noopener\">ISO21940-11:2016<\/a>,which remains published,has Amendment1:2022 and was at systematic-review stage90.20 when checked in July2026. Mass\u00d7length (for example g\u00b7mm) and mass\u00d7length per rotor mass (for example g\u00b7mm\/kg) are different quantities;this mass-only converter calculates neither an unbalance tolerance nor acceptance. Exact normative clauses and project criteria require the controlled standard.<\/p><\/section>\n<section class=\"mu-section\"><h2>What was corrected<\/h2><p>The former title and introduction called kg,lb and oz both mass and weight units even though the calculator produced no force. It also used the bare symbols \u201clb\u201d and \u201coz\u201d,pre-filled a result,accepted negative masses and numeric prefixes through <span class=\"mu-code\">parseFloat<\/span>,and did not disclose display rounding. The replacement is explicitly a mass converter,uses complete-number validation,starts blank and labels avoirdupois,troy,short-ton and long-ton systems.<\/p><p>Unsourced object-mass examples and steel \u201cweight\u201d estimates were removed because actual mass depends on dimensions,density,tolerances,configuration and rated container data. The exact unit definitions remain;engineering estimates belong in documented geometry\/material calculators.<\/p><\/section>\n<footer class=\"mu-footer\">\u00a92024\u20132026 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a> \u00b7 Scientific review July2026<\/footer><\/div>\n<script>(function(){'use strict';function $(id){return document.getElementById(id)}var UNITS=[{k:'mg',n:'milligram',s:'mg',f:0.000001},{k:'g',n:'gram',s:'g',f:0.001},{k:'kg',n:'kilogram',s:'kg',f:1},{k:'tonne',n:'tonne (metric ton)',s:'t',f:1000},{k:'grain',n:'grain',s:'gr',f:0.00006479891},{k:'oz_av',n:'ounce avoirdupois',s:'oz av',f:0.028349523125},{k:'lb_av',n:'pound avoirdupois',s:'lb av',f:0.45359237},{k:'stone',n:'stone',s:'st',f:6.35029318},{k:'short_ton',n:'short ton (US)',s:'short ton',f:907.18474},{k:'long_ton',n:'long ton (Imperial)',s:'long ton',f:1016.0469088},{k:'troy_oz',n:'troy ounce',s:'oz t',f:0.0311034768},{k:'carat',n:'carat',s:'ct',f:0.0002}];var MAP={};UNITS.forEach(function(u){MAP[u.k]=u});function num(s){s=String(s).trim();if(!s||s.includes('.')&&s.includes(',')||!\/^[+]?(?:\\d+(?:[.,]\\d*)?|[.,]\\d+)(?:[eE][+-]?\\d+)?$\/.test(s))return NaN;var n=Number(s.replace(',','.'));return Number.isFinite(n)&&n<=1e100?n:NaN}function fmt(n){if(n===0)return'0';var a=Math.abs(n);return a>=1e12||a<1e-9?n.toExponential(11):Number(n.toPrecision(12)).toLocaleString('en-US',{maximumFractionDigits:20})}function clear(){$('mu-rgrid').innerHTML='';$('mu-summary').textContent='\u2014';$('mu-results').hidden=true;$('mu-results').dataset.json=''}function fail(m){clear();$('mu-error').textContent=m}function calc(){var raw=$('mu-value').value,unit=$('mu-unit').value,started=raw.trim()||unit;if(!started){$('mu-error').textContent='';clear();return}var x=num(raw);if(!MAP[unit]){fail('Select the mass unit attached to the source value.');return}if(!Number.isFinite(x)){fail('Enter one complete finite non-negative number;use decimal point or decimal comma,not both.');return}var kg=x*MAP[unit].f;if(!Number.isFinite(kg)){fail('The result exceeds the supported numerical range.');return}var values={},html='';for(var i=0;i<UNITS.length;i++){var u=UNITS[i],v=kg\/u.f;if(!Number.isFinite(v)){fail('The result exceeds the supported numerical range.');return}values[u.k]=v;html+='<article class=\"mu-card\"><h3>'+u.n+'<\/h3><div class=\"mu-val\">'+fmt(v)+'<\/div><div class=\"mu-unit\">'+u.s+'<\/div><\/article>'}$('mu-error').textContent='';$('mu-rgrid').innerHTML=html;$('mu-summary').textContent=fmt(x)+' '+MAP[unit].s+' = '+fmt(kg)+' kg;mass conversion only.';$('mu-results').dataset.json=JSON.stringify({input_value:x,input_unit:unit,canonical_kg:kg,values:values});$('mu-results').hidden=false}$('mu-form').addEventListener('input',calc);$('mu-form').addEventListener('change',calc);calc()})();<\/script>\n","protected":false},"excerpt":{"rendered":"<p>Bezplatn\u00fd online prevodn\u00edk hmotnosti a hmotnosti. Prevod medzi kg, g, mg, tona, lb, oz, stone, short ton, long ton a grain. V\u0161etky jednotky sa zobrazuj\u00fa s\u00fa\u010dasne.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[],"tags":[],"class_list":["post-100150","calculator","type-calculator","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/sk\/wp-json\/wp\/v2\/calculator\/100150","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/sk\/wp-json\/wp\/v2\/calculator"}],"about":[{"href":"https:\/\/vibromera.eu\/sk\/wp-json\/wp\/v2\/types\/calculator"}],"version-history":[{"count":3,"href":"https:\/\/vibromera.eu\/sk\/wp-json\/wp\/v2\/calculator\/100150\/revisions"}],"predecessor-version":[{"id":102487,"href":"https:\/\/vibromera.eu\/sk\/wp-json\/wp\/v2\/calculator\/100150\/revisions\/102487"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/sk\/wp-json\/wp\/v2\/media?parent=100150"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/sk\/wp-json\/wp\/v2\/categories?post=100150"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/sk\/wp-json\/wp\/v2\/tags?post=100150"}],"curies":[{"name":"pracovn\u00fd list","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}