{"id":100072,"date":"2026-02-15T20:15:00","date_gmt":"2026-02-15T20:15:00","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100072"},"modified":"2026-07-12T00:44:27","modified_gmt":"2026-07-12T00:44:27","slug":"cutting-speed-rpm","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/vi\/calculators\/cutting-speed-rpm\/","title":{"rendered":"Cutting Surface Speed \u2194 Spindle Speed | Exact Conversion"},"content":{"rendered":"\r\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Cutting Surface Speed and Spindle Speed Arithmetic\",\"description\":\"Convert exactly between cutting surface speed and spindle rotational speed using the applicable cutting or machined diameter, in metric or inch units, without generic material presets.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/cutting-speed-rpm\/\",\"applicationCategory\":\"Engineering 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a:hover{text-decoration:underline}\r\n.vc-footer-links{margin-top:8px;font-size:12px}\r\n.vc-footer-links a{margin:0 8px}\r\n@media print{.vc-section-body{max-height:none!important}.vc-faq-a{max-height:none!important}.vc-results{max-height:none!important;padding:24px!important}.vc-copy-btn,.vc-section-chevron,.vc-faq-chevron,.vc-presets,.vc-promo{display:none!important}}\r\n<\/style>\r\n<div class=\"vc-calculator\" id=\"vc-cutting-speed-rpm\"><header class=\"vc-header\"><p class=\"vc-header-eyebrow\">Exact circumference arithmetic<\/p><h1 class=\"vc-header-title\">Cutting Surface Speed \u2194 Spindle Speed<\/h1><p class=\"vc-header-subtitle\">Convert between peripheral cutting surface speed and spindle rotational speed using the actual cutting diameter for the operation. Metric and inch formulas are evaluated directly in their stated units.<\/p><div class=\"vc-badges\"><span class=\"vc-badge\">Bidirectional<\/span><span class=\"vc-badge\">Metric \/ inch<\/span><span class=\"vc-badge\">No generic material presets<\/span><\/div><\/header>\r\n<div class=\"vc-card\"><form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\"><div class=\"vc-form-grid\"><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-units\">Unit system<\/label><select class=\"vc-select\" id=\"vc-units\"><option value=\"metric\">Metric: mm and m\/min<\/option><option value=\"inch\">Inch: in and ft\/min<\/option><\/select><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-mode\">Calculate<\/label><select class=\"vc-select\" id=\"vc-mode\"><option value=\"rpm\">Spindle speed from surface speed<\/option><option value=\"surface\">Surface speed from spindle speed<\/option><\/select><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-d\">Applicable cutting\/machined diameter D <span class=\"vc-label-hint\" id=\"vc-d-unit\">(mm; &gt;0)<\/span><\/label><input class=\"vc-input\" id=\"vc-d\" type=\"text\" inputmode=\"decimal\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-value\"><span id=\"vc-value-name\">Cutting surface speed v<sub>c<\/sub><\/span> <span class=\"vc-label-hint\" id=\"vc-value-unit\">(m\/min; &gt;0)<\/span><\/label><input class=\"vc-input\" id=\"vc-value\" type=\"text\" inputmode=\"decimal\"><\/div><div class=\"vc-field vc-field-full\"><label class=\"vc-label\" for=\"vc-source\">Diameter and cutting-data source; tool\/workpiece, material and operation basis<\/label><input class=\"vc-input\" id=\"vc-source\" type=\"text\" maxlength=\"300\"><\/div><\/div><p id=\"vc-error\" role=\"alert\" style=\"margin:.75rem 0 0;color:#b42318\"><\/p><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>Input gate:<\/strong> for milling use the cutting diameter at the actual cutting depth; for turning use the machined diameter at the evaluated location. Obtain the recommended cutting speed from the tool maker for the actual tool grade, work material\/condition, operation, engagement, coolant and machine constraints.<\/p><\/div><\/form><div class=\"vc-results\" id=\"vc-results\"><div class=\"vc-results-head\"><h2 class=\"vc-results-title\">Kinematic conversion<\/h2><button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\">Copy<\/button><\/div><div class=\"vc-result-grid\"><div class=\"vc-rcard vc-rcard-primary\"><div class=\"vc-rcard-label\" id=\"vc-r-label\">Calculated spindle speed<\/div><div class=\"vc-rcard-value\" id=\"vc-r-primary\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Surface speed<\/div><div class=\"vc-rcard-value\" id=\"vc-r-metric\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Surface speed<\/div><div class=\"vc-rcard-value\" id=\"vc-r-inch\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Spindle speed<\/div><div class=\"vc-rcard-value\" id=\"vc-r-rpm\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Circumference<\/div><div class=\"vc-rcard-value\" id=\"vc-r-circ\">\u2014<\/div><\/div><\/div><p id=\"vc-r-note\" style=\"margin:0;color:var(--vc-ink-secondary)\"><\/p><\/div><\/div>\r\n<div class=\"vc-section vc-open\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udcd8<\/span><span class=\"vc-section-title\">Formula, diameter and recommendation boundary<\/span><\/span><\/button><div class=\"vc-section-body\"><div class=\"vc-section-inner vc-theory\"><div class=\"vc-formula-box\">Metric: v<sub>c<\/sub>[m\/min] = \u03c0D[mm]n[r\/min]\/1000; &nbsp; n = 1000v<sub>c<\/sub>\/(\u03c0D)<\/div><div class=\"vc-formula-box\">Inch: v<sub>c<\/sub>[ft\/min] = \u03c0D[in]n[r\/min]\/12; &nbsp; n = 12v<sub>c<\/sub>\/(\u03c0D)<\/div><p>These are circumference-times-revolutions unit identities, not ISO acceptance formulas. <a href=\"https:\/\/cdn.sandvik.coromant.com\/files\/sitecollectiondocuments\/services\/metal-cutting-e-learning\/formulas-and-definitions\/formulas-and-deinitions-for-milling-metric-enu.pdf\" target=\"_blank\" rel=\"noopener\">Sandvik Coromant metric milling formulas<\/a> define D<sub>cap<\/sub> as the cutting diameter at cutting depth a<sub>p<\/sub> and give both metric equations. The official <a href=\"https:\/\/cdn.sandvik.coromant.com\/files\/sitecollectiondocuments\/services\/metal-cutting-e-learning\/formulas-and-definitions\/formulas-and-deinitions-for-milling-inch-enu.pdf\" target=\"_blank\" rel=\"noopener\">inch milling formula sheet<\/a> gives the corresponding factor 12.<\/p><p>Cutting surface speed is a kinematic quantity, not an intrinsic material property. A recommended value is an operating selection. <a href=\"https:\/\/www.kennametal.com\/au\/en\/resources\/engineering-calculators\/miscellaneous\/speed-and-feed.html\" target=\"_blank\" rel=\"noopener\">Kennametal&#8217;s official guidance<\/a> identifies work-material hardness\/heat treatment\/alloy, tool material\/shape\/condition, coolant and fixture stability as relevant inputs. The former generic HSS\/carbide material table and presets did not identify these conditions and have been removed.<\/p><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>No machine-command guarantee:<\/strong> compare calculated n with tool-holder\/tool maximum speed, spindle range, workholding\/chuck limits, workpiece integrity, balance, machine torque\/power and OEM restrictions. Never exceed the lowest applicable rated speed.<\/p><\/div><\/div><\/div><\/div><footer class=\"vc-footer\"><p>\u00a9 2024\u20132026 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a><\/p><p>Exact kinematic conversion from sourced inputs; no automatic cutting-data recommendation. Scientific review: July 2026.<\/p><\/footer><\/div>\r\n<script>(function(){'use strict';function $(i){return document.getElementById(i)}function raw(v){var s=String(v).trim().replace(\/\\s+\/g,'');if(!\/^[+]?(?:\\d+(?:[.,]\\d*)?|[.,]\\d+)$\/.test(s))return NaN;return Number(s.replace(',','.'))}function pos(v){var x=raw(v);return Number.isFinite(x)&&x>0?x:NaN}function f(x){return x.toFixed(9).replace(\/(\\.\\d*?)0+$\/,'$1').replace(\/\\.$\/,'')}function labels(){var inch=$('vc-units').value==='inch',surface=$('vc-mode').value==='surface';$('vc-d-unit').textContent=inch?'(in; >0)':'(mm; >0)';$('vc-value-name').innerHTML=surface?'Spindle speed n':'Cutting surface speed v<sub>c<\/sub>';$('vc-value-unit').textContent=surface?'(r\/min; >0)':(inch?'(ft\/min; >0)':'(m\/min; >0)')}function calc(){labels();var units=$('vc-units').value,mode=$('vc-mode').value,D=pos($('vc-d').value),x=pos($('vc-value').value),source=$('vc-source').value.trim(),any=Array.from(document.querySelectorAll('#vc-form input')).some(function(q){return q.value.trim()});if(!Number.isFinite(D)||!Number.isFinite(x)||!source){$('vc-error').textContent=any?'Enter D>0,a positive speed,and a traceable diameter\/cutting-data basis.':'';$('vc-results').classList.remove('vc-visible');return}var Dmm=units==='inch'?D*25.4:D,n,vm;if(mode==='rpm'){vm=(units==='inch'?x*0.3048:x);n=1000*vm\/(Math.PI*Dmm)}else{n=x;vm=Math.PI*Dmm*n\/1000}var vft=vm\/0.3048,cmm=Math.PI*Dmm;$('vc-error').textContent='';$('vc-r-label').textContent=mode==='rpm'?'Calculated spindle speed':'Calculated cutting surface speed';$('vc-r-primary').textContent=mode==='rpm'?f(n)+' r\/min':(units==='inch'?f(vft)+' ft\/min':f(vm)+' m\/min');$('vc-r-metric').textContent=f(vm)+' m\/min';$('vc-r-inch').textContent=f(vft)+' ft\/min';$('vc-r-rpm').textContent=f(n)+' r\/min';$('vc-r-circ').textContent=units==='inch'?f(cmm\/25.4)+' in':f(cmm)+' mm';$('vc-r-note').textContent='Basis: '+source+' | Kinematic conversion only; no recommended cutting speed selected.';$('vc-results').classList.add('vc-visible');var u=new URL(location),v={unit_system:units,calculation_mode:mode,diameter:D,input_value:x,input_basis:source};Object.keys(v).forEach(function(q){u.searchParams.set(q,v[q])});history.replaceState(null,'',u.toString())}$('vc-form').addEventListener('input',calc);$('vc-form').addEventListener('change',calc);$('vc-copy-btn').addEventListener('click',function(){if(navigator.clipboard)navigator.clipboard.writeText($('vc-results').innerText)});document.querySelectorAll('.vc-section-toggle').forEach(function(b){b.addEventListener('click',function(){var s=this.closest('.vc-section');s.classList.toggle('vc-open');this.setAttribute('aria-expanded',s.classList.contains('vc-open'))})});var p=new URLSearchParams(location.search),map={unit_system:'vc-units',calculation_mode:'vc-mode',diameter:'vc-d',input_value:'vc-value',input_basis:'vc-source'};Object.keys(map).forEach(function(q){if(p.has(q))$(map[q]).value=p.get(q)});calc()})();<\/script>\r\n","protected":false},"excerpt":{"rendered":"<p>Convert exactly between cutting surface speed and spindle rotational speed using the actual cutting or machined diameter, with metric\/inch units and no generic material presets.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[],"tags":[],"class_list":["post-100072","calculator","type-calculator","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/vi\/wp-json\/wp\/v2\/calculator\/100072","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/vi\/wp-json\/wp\/v2\/calculator"}],"about":[{"href":"https:\/\/vibromera.eu\/vi\/wp-json\/wp\/v2\/types\/calculator"}],"version-history":[{"count":2,"href":"https:\/\/vibromera.eu\/vi\/wp-json\/wp\/v2\/calculator\/100072\/revisions"}],"predecessor-version":[{"id":102362,"href":"https:\/\/vibromera.eu\/vi\/wp-json\/wp\/v2\/calculator\/100072\/revisions\/102362"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/vi\/wp-json\/wp\/v2\/media?parent=100072"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/vi\/wp-json\/wp\/v2\/categories?post=100072"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/vi\/wp-json\/wp\/v2\/tags?post=100072"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}