{"id":82596,"date":"2026-10-17T23:46:23","date_gmt":"2026-10-17T21:46:23","guid":{"rendered":"https:\/\/panelsandwich.org\/sandwich-panel-calculator-panels-m%c2%b2-purlins-and-screws\/"},"modified":"2026-10-18T02:46:16","modified_gmt":"2026-10-18T00:46:16","slug":"sandwich-panel-calculator","status":"publish","type":"page","link":"https:\/\/panelsandwich.org\/en\/sandwich-panel-calculator\/","title":{"rendered":"Sandwich Panel Calculator: panels, m\u00b2, purlins, and screws"},"content":{"rendered":"<div class=\"product\"><div class=\"product\">\n<div style=\"background-color:#f4f5f7;font-family:'Segoe UI',Roboto,Helvetica,Arial,sans-serif;line-height:1.6;color:#333;padding:20px;\">\n<div style=\"max-width:800px;margin:0 auto;background-color:#fff;border-radius:8px;padding:40px;box-shadow:0 10px 40px -10px rgba(16,24,40,.15);border-top:5px solid #fba905;\">\n<p style=\"margin:0 0 6px 0;color:#101828;font-size:13px;font-weight:700;letter-spacing:.5px;text-transform:uppercase;\">Free tool<\/p>\n<h1 style=\"color:#101828;font-size:2rem;line-height:1.2;margin:0 0 18px 0;font-weight:700;\">Sandwich panel calculator<\/h1>\n<p style=\"margin-bottom:18px;color:#444;\">Work out how many <strong style=\"color:#101828;\">sandwich panels<\/strong> you need for your roof or fa\u00e7ade, how many square metres to order, how many purlins the structure needs, and an estimate of screws and trims. It is a guide to prepare your quote: when you request it, we confirm sizes, thickness and fixings.<\/p>\n<style>\n#ps-calc{border:1px solid #e3e8ef;border-radius:10px;padding:22px;margin:10px 0 30px;background:#fafbfc}\n#ps-calc .row{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px 18px}\n#ps-calc label{display:block;font-weight:600;color:#101828;font-size:15px;margin-bottom:4px}\n#ps-calc small{display:block;color:#667085;font-size:13px;margin-top:3px;line-height:1.4}\n#ps-calc input,#ps-calc select{width:100%;box-sizing:border-box;padding:10px 12px;border:1px solid #cfd6e0;border-radius:8px;font-size:16px;background:#fff}\n#ps-calc .full{grid-column:1\/-1}\n#ps-calc .res{margin-top:20px;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}\n#ps-calc .card{background:#fff;border:1px solid #e3e8ef;border-left:4px solid #fba905;border-radius:8px;padding:12px 14px}\n#ps-calc .card b{display:block;font-size:22px;color:#101828;line-height:1.2}\n#ps-calc .card span{font-size:13px;color:#475467}\n#ps-calc .note{margin-top:14px;font-size:14px;color:#475467}\n#ps-calc .warn{margin-top:12px;padding:10px 12px;border-radius:8px;background:#fff7e6;color:#7a4a00;font-size:14px;display:none}\n@media(max-width:600px){#ps-calc .row,#ps-calc .res{grid-template-columns:1fr}}\n<\/style>\n<div id=\"ps-calc\">\n<div class=\"row\">\n<div class=\"full\"><label for=\"pc-tipo\">What are you covering?<\/label><select id=\"pc-tipo\"><option value=\"2\">Dual-pitch roof<\/option><option value=\"1\">Single-pitch roof<\/option><option value=\"f\">Fa\u00e7ade or wall<\/option><\/select><\/div>\n<div><label for=\"pc-largo\" id=\"pc-largo-l\">Length of each roof slope (m)<\/label><input id=\"pc-largo\" type=\"number\" min=\"0\" step=\"0.01\" value=\"6\" inputmode=\"decimal\"><small id=\"pc-largo-h\">Along the slope, from the ridge to the edge.<\/small><\/div>\n<div><label for=\"pc-ancho\" id=\"pc-ancho-l\">Roof width (m)<\/label><input id=\"pc-ancho\" type=\"number\" min=\"0\" step=\"0.01\" value=\"10\" inputmode=\"decimal\"><small id=\"pc-ancho-h\">Measured along the ridge.<\/small><\/div>\n<div id=\"pc-alero-w\"><label for=\"pc-alero\">Overhang (m)<\/label><input id=\"pc-alero\" type=\"number\" min=\"0\" step=\"0.01\" value=\"0.2\" inputmode=\"decimal\"><small>How far the panel sticks out past the edge.<\/small><\/div>\n<div><label for=\"pc-util\">Panel effective width<\/label><select id=\"pc-util\"><option value=\"1\">1.00 m (roof, tile and most fa\u00e7ade panels)<\/option><option value=\"1.1\">1.10 m (some fa\u00e7ade panels)<\/option><\/select><\/div>\n<div id=\"pc-sep-w\"><label for=\"pc-sep\">Purlin spacing (m)<\/label><input id=\"pc-sep\" type=\"number\" min=\"0.5\" max=\"3\" step=\"0.05\" value=\"1.2\" inputmode=\"decimal\"><small>Usually between 1 and 1.5 m, depending on thickness.<\/small><\/div>\n<div><label for=\"pc-fij\">Fixings per panel and support<\/label><input id=\"pc-fij\" type=\"number\" min=\"1\" max=\"8\" step=\"1\" value=\"3\" inputmode=\"numeric\"><small>A guide; it depends on wind and location.<\/small><\/div>\n<div id=\"pc-hueco-w\" style=\"display:none\"><label for=\"pc-hueco\">Door and window openings (m\u00b2)<\/label><input id=\"pc-hueco\" type=\"number\" min=\"0\" step=\"0.1\" value=\"0\" inputmode=\"decimal\"><\/div>\n<\/div>\n<div class=\"res\" aria-live=\"polite\">\n<div class=\"card\"><b id=\"r-pan\">\u2014<\/b><span>panels<\/span><\/div>\n<div class=\"card\"><b id=\"r-lp\">\u2014<\/b><span id=\"r-lp-t\">length of each panel<\/span><\/div>\n<div class=\"card\"><b id=\"r-m2\">\u2014<\/b><span>m\u00b2 of panel to order<\/span><\/div>\n<div class=\"card\"><b id=\"r-sup\">\u2014<\/b><span>m\u00b2 of surface to cover<\/span><\/div>\n<div class=\"card\"><b id=\"r-cor\">\u2014<\/b><span id=\"r-cor-t\">purlins (support lines)<\/span><\/div>\n<div class=\"card\"><b id=\"r-tor\">\u2014<\/b><span>approximate screws<\/span><\/div>\n<div class=\"card full\" style=\"grid-column:1\/-1\"><b id=\"r-rem\" style=\"font-size:17px\">\u2014<\/b><span>approximate trims (linear metres)<\/span><\/div>\n<\/div>\n<div class=\"warn\" id=\"r-warn\"><\/div>\n<p class=\"note\">Panels are made to measure and most go up to about 16 m long; if your roof slope is longer, two overlapping panels are used. Want a quote with these sizes? <a href=\"https:\/\/panelsandwich.org\/en\/contact\/\" style=\"color:#101828;text-decoration:none;border-bottom:2px solid #fba905;font-weight:600;\">Ask for it here<\/a> or call us on +34 683 442 608.<\/p>\n<\/div>\n<script>(function(){var $=function(i){return document.getElementById(i)};function n(i){var v=parseFloat(String($(i).value).replace(',','.'));return isFinite(v)&&v>0?v:0}function f(x,d){return x.toLocaleString('en-GB',{maximumFractionDigits:d,minimumFractionDigits:0})}function calc(){var t=$('pc-tipo').value,fa=(t==='f'),u=parseFloat($('pc-util').value),L=n('pc-largo'),A=n('pc-ancho'),al=fa?0:n('pc-alero'),s=n('pc-sep'),fj=Math.max(1,Math.round(n('pc-fij'))),fal=t==='2'?2:1,w=$('r-warn');$('pc-largo-l').textContent=fa?'Wall height (m)':'Length of each roof slope (m)';$('pc-largo-h').textContent=fa?'Panels fitted vertically.':'Along the slope, from the ridge to the edge.';$('pc-ancho-l').textContent=fa?'Wall length (m)':'Roof width (m)';$('pc-ancho-h').textContent=fa?'Total length of all the walls to cover.':'Measured along the ridge.';$('pc-alero-w').style.display=fa?'none':'';$('pc-hueco-w').style.display=fa?'':'none';$('r-cor-t').textContent=fa?'support profile lines':'purlins per slope';if(!L||!A||!u){['r-pan','r-lp','r-m2','r-sup','r-cor','r-tor','r-rem'].forEach(function(i){$(i).textContent='\u2014'});w.style.display='none';return}var lp=L+al,piezas=lp>16?Math.ceil(lp\/16):1,porF=Math.ceil(A\/u-1e-9),pan=porF*fal*piezas,m2=porF*u*lp*fal,sup=A*L*fal-(fa?n('pc-hueco'):0),cor=s?Math.ceil(L\/s-1e-9)+1:0,tor=porF*fal*cor*fj;$('r-pan').textContent=f(pan,0);$('r-lp').textContent=piezas>1?(piezas+' \u00d7 '+f(lp\/piezas+0.2,2)+' m'):f(lp,2)+' m';$('r-lp-t').textContent=piezas>1?'panels per row, overlapped (includes 0.2 m overlap)':'length of each panel';$('r-m2').textContent=f(m2,1);$('r-sup').textContent=f(Math.max(0,sup),1);$('r-cor').textContent=s?f(cor,0):'\u2014';$('r-tor').textContent=s?f(tor,0):'\u2014';var r=fa?('Corners: '+f(L*4,1)+' m \u00b7 base and top trims: '+f(A*2,1)+' m'):(t==='2'?('Ridge: '+f(A,1)+' m \u00b7 side trims: '+f(lp*4,1)+' m \u00b7 eaves trim: '+f(A*2,1)+' m'):('Top trim: '+f(A,1)+' m \u00b7 side trims: '+f(lp*2,1)+' m \u00b7 eaves trim: '+f(A,1)+' m'));$('r-rem').textContent=r;var m=[];if(piezas>1)m.push('The length is over 16 m: it is normally split into '+piezas+' overlapping panels.');if(s>1.5)m.push('Purlin spacing over 1.5 m needs a thicker panel; ask us.');w.innerHTML=m.join('<br>');w.style.display=m.length?'block':'none'}['pc-tipo','pc-largo','pc-ancho','pc-alero','pc-util','pc-sep','pc-fij','pc-hueco'].forEach(function(i){$(i).addEventListener('input',calc);$(i).addEventListener('change',calc)});calc()})();<\/script>\n<h2 style=\"color:#101828;font-size:1.6rem;margin-top:40px;margin-bottom:20px;border-bottom:2px solid #eee;padding-bottom:10px;font-weight:700;\">How the calculator works<\/h2>\n<ul style=\"margin:0 0 20px 0;padding-left:22px;\">\n<li style=\"margin-bottom:10px;color:#444;\"><strong style=\"color:#101828;\">Number of panels:<\/strong> width to cover divided by the panel effective width, rounded up, for each slope.<\/li>\n<li style=\"margin-bottom:10px;color:#444;\"><strong style=\"color:#101828;\">Length of each panel:<\/strong> the slope length plus the overhang. Above about 16 m it is split into two overlapping panels.<\/li>\n<li style=\"margin-bottom:10px;color:#444;\"><strong style=\"color:#101828;\">Purlins:<\/strong> slope length divided by the spacing, plus one. The right spacing depends on panel thickness and on wind and snow loads.<\/li>\n<li style=\"margin-bottom:10px;color:#444;\"><strong style=\"color:#101828;\">Screws:<\/strong> panels \u00d7 purlins \u00d7 fixings per support. This is an estimate; the real number depends on wind, height and roof zone.<\/li>\n<li style=\"margin-bottom:10px;color:#444;\"><strong style=\"color:#101828;\">Trims:<\/strong> linear metres of ridge, side and eaves trims. It does not include flashings against walls, chimneys or rooflights.<\/li>\n<\/ul>\n<p style=\"margin-bottom:18px;color:#444;\">To fine-tune your measurements, see our guides on <a href=\"https:\/\/panelsandwich.org\/en\/how-to-measure-sandwich-panel-correctly\/\" style=\"color:#101828;text-decoration:none;border-bottom:2px solid #fba905;font-weight:600;\">sandwich panel sizes<\/a>, <a href=\"https:\/\/panelsandwich.org\/en\/what-structure-you-need-before-installing-sandwich-panels\/\" style=\"color:#101828;text-decoration:none;border-bottom:2px solid #fba905;font-weight:600;\">structure and purlin spacing<\/a> and <a href=\"https:\/\/panelsandwich.org\/en\/how-much-does-a-meter-of-sandwich-panel-cost-today\/\" style=\"color:#101828;text-decoration:none;border-bottom:2px solid #fba905;font-weight:600;\">sandwich panel price per m\u00b2<\/a>.<\/p>\n<h2 style=\"color:#101828;font-size:1.6rem;margin-top:40px;margin-bottom:20px;border-bottom:2px solid #eee;padding-bottom:10px;font-weight:700;\">Frequently asked questions<\/h2>\n<div style=\"background-color:#f8f9fa;border-left:4px solid #fba905;padding:20px;margin-bottom:15px;border-radius:0 6px 6px 0;\"><h3 style=\"display:block;font-weight:bold;color:#101828;margin:0 0 8px 0;font-size:1rem;line-height:1.6;\">How many sandwich panels do I need for 100 m\u00b2?<\/h3><p style=\"margin:0;color:#555;\">It depends on the length of each panel. With 1 m effective width, a 6 m panel covers 6 m\u00b2, so 100 m\u00b2 needs 17 panels of 6 m. Enter your sizes in the calculator to get the exact number including the overhang.<\/p><\/div>\n<div style=\"background-color:#f8f9fa;border-left:4px solid #fba905;padding:20px;margin-bottom:15px;border-radius:0 6px 6px 0;\"><h3 style=\"display:block;font-weight:bold;color:#101828;margin:0 0 8px 0;font-size:1rem;line-height:1.6;\">How big is a sandwich panel?<\/h3><p style=\"margin:0;color:#555;\">The usual effective width is 1 m and the length is made to measure. Most panels go up to about 16 m; longer slopes use two overlapping panels.<\/p><\/div>\n<div style=\"background-color:#f8f9fa;border-left:4px solid #fba905;padding:20px;margin-bottom:15px;border-radius:0 6px 6px 0;\"><h3 style=\"display:block;font-weight:bold;color:#101828;margin:0 0 8px 0;font-size:1rem;line-height:1.6;\">How many screws does a sandwich panel need?<\/h3><p style=\"margin:0;color:#555;\">It is fixed to every purlin, usually with several fixings per support depending on the model and local wind. The calculator gives an estimate; we specify the exact fixings when we prepare your quote.<\/p><\/div>\n<div style=\"background-color:#f8f9fa;border-left:4px solid #101828;padding:20px;margin:30px 0;border-radius:0 6px 6px 0;\"><span style=\"display:block;font-weight:bold;color:#101828;margin-bottom:5px;text-transform:uppercase;font-size:.85rem;letter-spacing:.5px;\">Already have your measurements?<\/span><p style=\"margin:0;color:#555;\">We prepare a quote with panels, trims and fixings. <a href=\"https:\/\/panelsandwich.org\/en\/contact\/\" style=\"color:#101828;text-decoration:none;border-bottom:2px solid #fba905;font-weight:600;\">Request a quote<\/a> or call us on +34 683 442 608.<\/p><\/div>\n<\/div>\n<\/div>\n<\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>Free tool Sandwich panel calculator Work out how many sandwich panels you need for your roof or fa\u00e7ade, how many square metres to order, how many purlins the structure needs, and an estimate of screws and trims. It is a guide to prepare your quote: when you request it, we confirm sizes, thickness and fixings. [&hellip;]<\/p>\n","protected":false},"author":6055,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-82596","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/panelsandwich.org\/en\/wp-json\/wp\/v2\/pages\/82596","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/panelsandwich.org\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/panelsandwich.org\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/panelsandwich.org\/en\/wp-json\/wp\/v2\/users\/6055"}],"replies":[{"embeddable":true,"href":"https:\/\/panelsandwich.org\/en\/wp-json\/wp\/v2\/comments?post=82596"}],"version-history":[{"count":3,"href":"https:\/\/panelsandwich.org\/en\/wp-json\/wp\/v2\/pages\/82596\/revisions"}],"predecessor-version":[{"id":83040,"href":"https:\/\/panelsandwich.org\/en\/wp-json\/wp\/v2\/pages\/82596\/revisions\/83040"}],"wp:attachment":[{"href":"https:\/\/panelsandwich.org\/en\/wp-json\/wp\/v2\/media?parent=82596"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}