Kegs calculo

function calculate() {
        var avgDays = _self.data.ales / 100 * 14 + 30 * (1 - (_self.data.ales || 0) / 100),
            batches = 360 / avgDays,
            annualCapacity = batches * _self.data.fermentCapacity,
            barrelsKegged = annualCapacity * (_self.data.kegged / 100) * (_self.data.turnover / 52),
            halfSplit = Math.ceil(barrelsKegged * ((_self.data.half || 0) / 100) * 2),
            sixthSplit = Math.ceil(barrelsKegged * ((_self.data.sixth || 0) / 100) * 6),
            quarterSplit = Math.ceil(barrelsKegged * (1 - ((_self.data.half || 0) / 100 + (_self.data.sixth || 0) / 100)) * 4),
            totalKegs = halfSplit + quarterSplit + sixthSplit;
        _self.totals = {
            half: halfSplit || 0,
            quarter: quarterSplit || 0,
            sixth: sixthSplit || 0,
            total: totalKegs || 0
        }
    }