One Rep Max Calculator

One Rep Max Calculator

Use this One Rep Max (1RM) Calculator to estimate the maximum weight you can lift for a single repetition based on the number of repetitions you can perform with a certain weight. For the most accurate estimate, use a weight you can lift between 1 and 10 times.

i
Modify the values and click the Calculate button to use
times (1-10)
Result

Enter weight and reps, then click Calculate.

'; ormResults = []; ormAverage = 0; } function ormExportPDF() { if (!ormResults.length) { alert('Please calculate first.'); return; } if (typeof window.jspdf === 'undefined') { alert('PDF library loading...'); return; } var jsPDF = window.jspdf.jsPDF; var doc = new jsPDF(); var unit = document.getElementById('orm-unit').value; var weight = document.getElementById('orm-weight').value; var reps = document.getElementById('orm-reps').value; var g = [90,154,58]; var gD = [45,100,30]; // Header doc.setFillColor(g[0],g[1],g[2]); doc.rect(0,0,210,28,'F'); doc.setFillColor(gD[0],gD[1],gD[2]); doc.rect(0,28,210,2,'F'); doc.setTextColor(255,255,255); doc.setFontSize(22); doc.setFont('helvetica','bold'); doc.text('One Rep Max Calculator',105,17,{align:'center'}); doc.setFontSize(10); doc.setFont('helvetica','normal'); doc.text('Estimation Results Report',105,25,{align:'center'}); // Input box var y = 40; doc.setDrawColor(200,200,200); doc.setFillColor(248,250,245); doc.roundedRect(14,y-5,182,28,3,3,'FD'); doc.setTextColor(60,60,60); doc.setFontSize(12); doc.setFont('helvetica','bold'); doc.text('Input Summary',20,y+2); doc.setFontSize(10); doc.setFont('helvetica','normal'); doc.setTextColor(80,80,80); doc.text('Weight: '+weight+' '+unit+' | Repetitions: '+reps+' | Date: '+new Date().toLocaleDateString(),20,y+14); // Formula results y = 78; doc.setTextColor(gD[0],gD[1],gD[2]); doc.setFontSize(14); doc.setFont('helvetica','bold'); doc.text('Estimated 1RM by Formula',14,y); y += 8; doc.setFillColor(g[0],g[1],g[2]); doc.rect(14,y,88,9,'F'); doc.rect(104,y,92,9,'F'); doc.setTextColor(255,255,255); doc.setFontSize(9); doc.text('Formula',18,y+6.5); doc.text('1RM ('+unit+')',68,y+6.5); doc.text('Formula',108,y+6.5); doc.text('1RM ('+unit+')',160,y+6.5); y += 9; var left = ormResults.slice(0,4); var right = ormResults.slice(4); var rH = 8; for (var i=0; i