{"id":1195,"date":"2026-07-08T07:00:54","date_gmt":"2026-07-08T05:00:54","guid":{"rendered":"https:\/\/printiteasy.eu\/kennisbank\/spine-calculator\/"},"modified":"2026-08-31T12:33:03","modified_gmt":"2026-08-31T10:33:03","slug":"spine-calculator","status":"publish","type":"page","link":"https:\/\/printiteasy.eu\/en\/knowledge-base\/spine-calculator\/","title":{"rendered":"Spine width calculator"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Do you want to <strong>calculate the spine width<\/strong> of your book? Use the calculator below: on the basis of the page count, the paper type and the binding, you immediately work out how wide the spine of your cover has to be. That way your cover design fits the book block exactly.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Spine width calculator<\/h2>\n\n\n\n<div id=\"pie-spine\" class=\"pie-spine\">\n <div class=\"sp-row\"><label>Bindwijze<\/label><div class=\"sp-bind\"><button type=\"button\" class=\"sp-b active\" data-board=\"4\">Hardcover<\/button><button type=\"button\" class=\"sp-b\" data-board=\"0\">Softcover<\/button><\/div><\/div>\n <div class=\"sp-row\"><label for=\"sp-pages\">Aantal pagina&#8217;s<\/label><input id=\"sp-pages\" type=\"number\" min=\"4\" step=\"2\" value=\"48\"><\/div>\n <div class=\"sp-row\"><label for=\"sp-paper\">Papiersoort binnenwerk<\/label><select id=\"sp-paper\"><option data-mm=\"0.09\">90 g\/m&sup2; mat<\/option><option data-mm=\"0.115\" selected>115 g\/m&sup2; mat<\/option><option data-mm=\"0.13\">135 g\/m&sup2; glans<\/option><option data-mm=\"0.16\">150 g\/m&sup2; mat<\/option><option data-mm=\"0.19\">170 g\/m&sup2; mat<\/option><option data-mm=\"0.11\">80 g\/m&sup2; romandruk<\/option><option data-mm=\"0.13\">90 g\/m&sup2; romandruk<\/option><\/select><\/div>\n <div class=\"sp-out\">Geschatte rugdikte: <strong id=\"sp-res\">&#8211;<\/strong><\/div>\n <p class=\"sp-note\" id=\"sp-note\"><\/p>\n<\/div>\n<style>\n.pie-spine{max-width:520px;border:1px solid #e2e8f0;border-radius:14px;padding:22px;background:#fff}\n.pie-spine .sp-row{margin-bottom:16px}\n.pie-spine label{display:block;font-weight:600;color:#334155;margin-bottom:6px;font-size:.95rem}\n.pie-spine input,.pie-spine select{width:100%;padding:11px 12px;border:1px solid #cbd5e1;border-radius:8px;font-size:1rem;background:#fff}\n.pie-spine .sp-bind{display:flex;gap:8px}\n.pie-spine .sp-b{flex:1;padding:11px 10px;border:1px solid #cbd5e1;border-radius:8px;background:#f8fafc;color:#475569;font-weight:600;cursor:pointer;font-size:.95rem}\n.pie-spine .sp-b.active{background:#1e3a8a;border-color:#1e3a8a;color:#fff}\n.pie-spine .sp-out{background:#eff4ff;border-radius:10px;padding:14px 16px;font-size:1.05rem;color:#1e293b}\n.pie-spine .sp-out strong{color:#1d4ed8;font-size:1.25rem}\n.pie-spine .sp-note{color:#64748b;font-size:.85rem;line-height:1.45;margin:10px 2px 0}\n<\/style>\n<script>\n(function(){\n var root=document.getElementById('pie-spine'); if(!root) return;\n var pages=root.querySelector('#sp-pages'), paper=root.querySelector('#sp-paper'), res=root.querySelector('#sp-res'), note=root.querySelector('#sp-note');\n var binds=root.querySelectorAll('.sp-b'); var board=4;\n function nl(x){ return x.toFixed(1).replace('.',','); }\n function calc(){\n  var n=parseInt(pages.value,10)||0; if(n<4)n=4;\n  var mm=parseFloat(paper.options[paper.selectedIndex].getAttribute('data-mm'))||0.115;\n  var interior=(n\/2)*mm; var spine=interior+board;\n  res.textContent=nl(spine)+' mm';\n  if(board>0){ note.textContent='Binnenwerk '+nl(interior)+' mm plus circa '+board+' mm bord (2 x 2 mm). Richtwaarde voor een hardcover, vraag bij twijfel een proefdruk aan.'; }\n  else { note.textContent='Rugdikte van het binnenwerk voor een softcover. De omslag telt nauwelijks mee. Richtwaarde, vraag bij twijfel een proefdruk aan.'; }\n }\n for(var i=0;i<binds.length;i++){ binds[i].addEventListener('click',function(){ for(var j=0;j<binds.length;j++){binds[j].classList.remove('active');} this.classList.add('active'); board=parseFloat(this.getAttribute('data-board'))||0; calc(); }); }\n pages.addEventListener('input',calc); paper.addEventListener('change',calc); calc();\n})();\n<\/script>\n\n\n\n<h2 class=\"wp-block-heading\">Why calculating the spine width matters<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The spine is the part of the cover that connects the front and the back. If the width is wrong, the text on the spine sits askew or the cover design does not run on neatly. With a hardcover in particular, and with a cover carrying a continuous image, an exact spine width is essential. That is why it is wise to calculate the spine width before you finalise your cover.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What does the spine width depend on?<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Page count:<\/strong> more pages means a thicker spine.<\/li>\n\n\n\n<li><strong>Paper type and weight:<\/strong> heavier and uncoated paper is thicker than light coated paper.<\/li>\n\n\n\n<li><strong>Binding:<\/strong> a hardcover has a different spine calculation than a softcover.<\/li>\n<\/ul>\n\n\n\n\n<h2 class=\"wp-block-heading\">How to calculate the spine width yourself<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If you want to know how the calculator arrives at its result, the rule for the book block is simple: <strong>page count &times; grammage &times; bulk factor &divide; 2000<\/strong>. You divide by 2000 because two pages together form one sheet of paper. The bulk factor belongs to the paper type and comes from our production specifications; for many text papers it is around 1.34.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">With a hardcover the book block sits between two board sides, so something is added: <strong>hardcover spine = book block spine + 2 &times; board thickness (2.25 mm)<\/strong>. If you choose a rounded spine instead of a square one, divide the result by 0.91; rounding pulls the spine slightly narrower. The calculator above does all of this automatically, including the correct bulk factor for the paper you choose.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Spine width and your cover design<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Supply your cover as one continuous surface: back board, spine and front board side by side, with 3 mm bleed all round and, for a hardcover, the turn-in as well. Keep spine texts at least 3 mm away from the fold lines. In production a tolerance of about 1 mm applies, and you notice that millimetre immediately if your title is set tight against the fold.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Below roughly fifty pages the spine is too narrow for legible text. Choose a saddle-stitched finish then, or deliberately leave the spine empty and put the title on the front board only. If you would rather see the full cover format straight away instead of just the spine, use the <a href=\"https:\/\/printiteasy.eu\/en\/create-cover\/\">cover creator<\/a> or the <a href=\"https:\/\/printiteasy.eu\/en\/knowledge-base\/book-cover-template\/\">technical drawing<\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Frequently asked questions about calculating the spine width<\/h2>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Why does my own calculation differ?<\/summary>\n<p class=\"wp-block-paragraph\">Usually because of the bulk factor. It differs per paper type, so calculate with the factor of the paper you actually choose. The same grammage can give a noticeably thicker spine with a different paper.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Do I have to state the spine width with my order?<\/summary>\n<p class=\"wp-block-paragraph\">No. You state format, page count, paper and binding, and we calculate the spine. If your cover does not match that result, we get in touch before we print.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary>Does the spine width change if I switch paper?<\/summary>\n<p class=\"wp-block-paragraph\">Yes, and sometimes considerably. If you go from 90 gsm offset to 130 gsm coated, your spine becomes thicker and your existing cover design no longer fits. So calculate the spine width only once your paper choice is final.<\/p>\n<\/details>\n\n\n\n<p class=\"wp-block-paragraph\">Unsure about the result or your paper choice? Have a look at our article on <a href=\"https:\/\/printiteasy.eu\/en\/knowledge-base\/paper-materials\/paper-weight-grammage\/\">paper weight and grammage<\/a>, or get in touch. We check your cover file free of charge before production, so that the spine width is guaranteed to be right.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What to do with the spine width<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The spine width is not just a number for your cover: it decides whether your title sits neatly centred on the spine. Take the calculated measurement across as the width of the spine panel in your layout program and place guides there, so nothing runs over the fold. Keep text on the spine at least 3 mm away from both fold lines; a small deviation is normal during binding, and that margin absorbs it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If you switch paper later or add a section, calculate again. The same 200 pages give a noticeably thicker spine on woodfree paper than on coated paper. If you want the complete cover at gross format straight away, use the <a href=\"https:\/\/printiteasy.eu\/en\/knowledge-base\/book-cover-template\/\">cover template<\/a>; the properties of each paper type are listed under <a href=\"https:\/\/printiteasy.eu\/en\/knowledge-base\/paper-materials\/\">paper and materials<\/a>. Export your cover according to Adobe\u2019s <a href=\"https:\/\/helpx.adobe.com\/indesign\/using\/exporting-publishing-pdf.html\" target=\"_blank\" rel=\"noopener\">guide to PDF export<\/a>.<\/p>\n\n\n","protected":false},"excerpt":{"rendered":"<p>Do you want to calculate the spine width of your book? Use the calculator below: on the basis of the page count, the paper type and the binding, you immediately work out how wide the spine of your cover has to be. That way your cover design fits the book block exactly. Spine width calculator&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":698,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":""},"class_list":["post-1195","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/pages\/1195","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/comments?post=1195"}],"version-history":[{"count":2,"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/pages\/1195\/revisions"}],"predecessor-version":[{"id":6345,"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/pages\/1195\/revisions\/6345"}],"up":[{"embeddable":true,"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/pages\/698"}],"wp:attachment":[{"href":"https:\/\/printiteasy.eu\/en\/wp-json\/wp\/v2\/media?parent=1195"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}