Просто сделайте промежуток position:absolute;
input + span {
position:absolute;
}
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" >
<div class="text-center">
<br>
<button class="btn-lg btn-danger col-10 " *ngIf="!login" (click)="isLogin()">Lets started</button>
<div class="center-block">
<div *ngIf="login">
<form (submit)="submit()">
<input class="col-auto-2 text-center" type="number" title="Eggs" name="egg" placeholder="Enter amount" [(ngModel)]="protein.eggs"><span>size</span><br>
<input class="col-auto-2 text-center" type="number" title="Breads" name="bread" placeholder="Enter amount" [(ngModel)]="protein.breads"><span>slices</span><br>
<input class="col-auto-2 text-center" type="number" title="Tuna" name="tuna" placeholder="Enter amount" [(ngModel)]="protein.tuna"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Meat" name="meat" placeholder="Enter amount" [(ngModel)]="protein.meat"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Cheese" name="cheese" placeholder="Enter amount" [(ngModel)]="protein.cheese"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Cottage" name="cottage" placeholder="Enter amount" [(ngModel)]="protein.cottage"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Quinoa" name="quinoa" placeholder="Enter amount" [(ngModel)]="protein.quinoa"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Almonds" name="almonds" placeholder="Enter amount" [(ngModel)]="protein.almonds"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Powder" name="powder" placeholder="Enter amount" [(ngModel)]="protein.powder"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Gainer" name="gainer" placeholder="Enter amount" [(ngModel)]="protein.gainer"><span>gram</span><br>
<input class="btn-secondary" type="button" value="Show" (click)="show()">
<input class="btn-secondary" type="submit" value="Save">
</form>
</div>
</div>
</div>
или вы можете использовать встроенную сетку
form {
display:inline-grid;
grid-template-columns: auto auto auto;
}
span {
text-align:left;
}
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" >
<div class="text-center">
<br>
<button class="btn-lg btn-danger col-10 " *ngIf="!login" (click)="isLogin()">Lets started</button>
<div class="center-block">
<div *ngIf="login">
<form (submit)="submit()">
<input class="col-auto-2 text-center" type="number" title="Eggs" name="egg" placeholder="Enter amount" [(ngModel)]="protein.eggs"><span>size</span><br>
<input class="col-auto-2 text-center" type="number" title="Breads" name="bread" placeholder="Enter amount" [(ngModel)]="protein.breads"><span>slices</span><br>
<input class="col-auto-2 text-center" type="number" title="Tuna" name="tuna" placeholder="Enter amount" [(ngModel)]="protein.tuna"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Meat" name="meat" placeholder="Enter amount" [(ngModel)]="protein.meat"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Cheese" name="cheese" placeholder="Enter amount" [(ngModel)]="protein.cheese"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Cottage" name="cottage" placeholder="Enter amount" [(ngModel)]="protein.cottage"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Quinoa" name="quinoa" placeholder="Enter amount" [(ngModel)]="protein.quinoa"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Almonds" name="almonds" placeholder="Enter amount" [(ngModel)]="protein.almonds"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Powder" name="powder" placeholder="Enter amount" [(ngModel)]="protein.powder"><span>gram</span><br>
<input class="col-auto-2 text-center" type="number" title="Gainer" name="gainer" placeholder="Enter amount" [(ngModel)]="protein.gainer"><span>gram</span><br>
<div>
<input class="btn-secondary" type="button" value="Show" (click)="show()">
<input class="btn-secondary" type="submit" value="Save">
</div>
</form>
</div>
</div>
</div>